Do we really want to take massive and public responsibility for what is still a bosses' government? No freaking way. It sticks in my craw to point at the David Lewis leadership as a good example of anything, but the old man publicly refused to enter a coalition with Pierre Trudeau in 1972-1974, supporting the Government of the day day-by-day instead, and maintaining our party's freedom of action.
In any case, the Liberals are falling apart over the issue already, if the Globe and Mail is to be believed: http://www.theglobeandmail.com/servlet/story/LAC.20081128.FISCALPARTY28PU/TPStory/National
"However, sources say that NDP Leader Jack Layton would not participate in a coalition government with Liberal Leader Stéphane Dion as prime minister. Similarly, the Liberal caucus does not want to fight an election with Mr. Dion at the helm." If Michael Valpy et al. are right, infighting between Rae and Ignatieff may just kill the deal anyhow.