Sounds very democratic, but its likely effect will be to siphon away votes from the Obama base. Progressives are famously unable to unite; and the presence of a third choice, particularly a centrist candidate, offering a palatable centrist/progressive alternative to Obama would be to the advantage of the GOP in a close race.
Here is what Ms. Whitman is quoted as saying in the dinner invitation:
"While most Americans hold centrist views, the small percentage of people on the fringes of both parties vote in the primaries and determine our options for president. The nominating system as it stands now is compromising our ability to govern, and therefore our effectiveness as a nation. That's why I've joined the board of Americans Elect, a nonpartisan nonprofit that's holding the first ever national online primary this year. Any registered voter can participate, and whoever the American people choose for president through Americans Elect will be on the ballot nationwide, right next to President Obama and the Republican nominee."
I'd like to give Ms. Whitman the benefit of the doubt and think there is only idealism and a deep love and respect for the will of the people behind her support. However, I suspect it's a pragmatic political "dirty trick" that GOP strategists hope will boost their chances of gaining the presidency in 2012.
If we could follow the money and see who's backing this it might tell the tale.