It seems ridiculous to speculate about what Dr. King might say to Barack Obama when we have a published record of what King actually did say to his government immediately before they had him assassinated. 
"Humanity is waiting for something other than blind imitation of the past. If we want truly to advance a step further, if we want to turn over a new leaf and really set a new man afoot, we must begin to turn mankind away from the long and desolate night of violence. May it not be that the new man the world needs is a nonviolent man? Longfellow said, "In this world a man must either be an anvil or a hammer." We must be hammers shaping a new society rather than anvils molded by the old. This not only will make us new men, but will give us a new kind of power. It will not be Lord Acton's image of power that tends to corrupt or absolute power that corrupts absolutely. It will be power infused with love and justice, that will change dark yesterdays into bright tomorrows, and lift us from the fatigue of despair to the buoyancy of hope. A dark, desperate, confused and sin-sick world waits for this new kind of man and this new kind of power." 
At the 23rd Annual Dr. Martin Luther King, Jr., Holiday Celebration in San Francisco staff members from the Martin Luther King Jr. Research and Education Institute had an opportunity to participate in the festivities and interact with those in attendance. Along with receiving bookmarks, buttons, pencils and a special note from Dr. King on political participation, attendees were asked to answer the question, "What would Dr. King want to say to Barack Obama?" 
But all speculation aside, Dr. King's actual comments appear in his last book, "Where Do We Go From Here: Chaos or Community?" The admonitions from that book seem as well-suited for Barack Obama now as they were for Lyndon Johnson in 1967 regarding war, poverty, racism, apartheid, imperialism and all the associated wastes of human and natural resources. If these typical forms of injustice aren't entertaining enough, they become even more surreal as Barack Obama now perpetuates them in the name of "Dr. King's Dream". Apparently, he thinks he can get away with this morbid and fraudulent strategy because his skin color is roughly the same as Dr. King's. But somebody needs to draw the line here, and it might as well be me. I don't see any other volunteers.
According to Dr. King, his dream came in two general phases: 1) abolish racial segregation, particularly in the southern United States, and 2) eradicate poverty worldwide.  The first four chapters of his last book discuss the successes, struggles and failures of phase one. The final two chapters and the appendix of his book outline his planned approach toward phase two. Dr. King was an extremely intelligent man, and the preceding is just a rough summary of his well organized book.
But nowhere in Dr. King's book is there any suggestion that the fulfillment of his "dream" might be the election of a black President who supports racist wars of economic aggression in the Middle East and the financial interests who sponsor them. He does emphatically insist that blacks must become politically involved, but not to advance the status quo or to "save Capitalism from itself".  The status quo doesn't need any help. It doesn't need to be "bailed out". It needs to be challenged and, for the most part, dismissed. I doubt that anyone had a greater understanding of the "deep structural change" necessary to accomplish phase two of his dream than Dr. Martin Luther King Jr. In fact, recent conclusions indicate he was murdered by his own government for daring to make such recommendations. 
Barack Obama is obviously intelligent enough to share Dr. King's understanding. But he also seems to driven to evade the public responsibility that should accompany that understanding. Is he merely dodging a bullet, or does he honestly believe he can rewrite history to somehow revise "Dr. King's Dream"? In his first ten weeks of office, when Obama makes decisions that are obviously not in the best interest of the people who elected him, it becomes brutally apparent that those decisions are in deliberate compliance with forces outside the democratic process. There isn't much question about who or what those corporate forces might be. The question is, why does such an intelligent man continue to lead in the same failed direction as his predecessors after so vehemently denouncing their approach?
Moreover, why does Barack Obama think he can pursue a plunder-for-profit agenda in the name of "Dr. King's Dream"? This is a sick fantasy that must be debunked and rebuked whether Obama plans to change his approach or not. If you want to lead this herd of stupid sheep to slaughter, Mr. Obama, then by all means do it. I won't begin to presume I could possibly stop you. But don't think for a minute that you can get away with blaming this painful fiasco on Dr. Martin Luther King Jr. or remotely associate yourself with him in the process.
Here's Dr. King:
The Assistant Director of the Office of Economic Opportunity, Hyman Bookbinder, in a frank statement on December 29, 1966, declared that the long-range costs of adequately implementing programs to fight poverty, ignorance and slums will reach one trillion dollars. He was not awed or dismayed by this prospect but instead pointed out that the growth of the gross national product during the same period makes this expenditure comfortably possible. It is, he said, as simple as this: "The poor can stop being poor if the rich are willing to become rich at a slower rate." Furthermore, he predicted that unless a "substantial sacrifice is made by the American people," the nation can expect further deterioration of the cities, increased antagonisms between races and continued disorders in the streets. He asserted that people are not informed enough to give adequate support to anti-poverty programs, and he leveled a share of the blame at the government because it "must do more to get people to understand the size of the problem."
The legal structures have in practice proved to be neither structures nor law. The sparse and insufficient collection of statutes is not a structure; it is barely a naked framework. Legislation that is evaded, substantially nullified and unenforced is a mockery of law. Significant progress has effectively been barred by equivocations and retreats of government -- the same government that was exultant when it sought political credit for enacting the measures.
The hard truth is that neither Negro nor white has yet done enough to expect the dawn of a new day. While much has been done, it has been accomplished by too few and on a scale too limited for the breadth of the goal. Freedom is not won by passive acceptance of suffering. Freedom is won by a struggle against suffering.
No great victories are won in a war for the transformation of a whole people without total participation. Less than this will not create a new society; it will only evoke more sophisticated token amelioration. Social justice and progress are the absolute guarantors of riot prevention. There is no other answer. Constructive social change will bring certain tranquility; evasions will merely encourage turmoil.
Power, properly understood, is the ability to achieve purpose. It is the strength required to bring about social, political or economic changes. In this sense power is not only desirable but necessary in order to implement the demands of love and justice. One of the greatest problems of history is that the concepts of love and power are usually contrasted as polar opposites. Love is identified with a resignation of power and power with a denial of love.
What is needed is a realization that love without power is sentimental and anemic. Power at its best is love implementing the demands of justice. Justice at its best is love correcting everything that stands against love. There is nothing essentially wrong with power. The problem is that in America power is unequally distributed. It is [the] collision of immoral power with powerless morality which constitutes the major crisis of our times.