Supposing that, between them, Labour and the Lib-Dems win one to two dozen more seats than OTL, so that the Conservatives still have a plurality, but that a Coalition of any two of the top three would mean a majority.
What does Nick Clegg do with this extra wiggle room? And what would TTL's coalition -- whether the Liberals form it with the Tories or Labour -- look like, in terms of cabinet make up, policy difference, what have you?
CONSOLIDATION: One thing I think is certain -- Gordon Brown would not get to remain Prime Minister...