Odds?

Odds against Cleggy pulling out of the coalition and trying to put Labour into power?

Long - but not impossibly so! Could win him back a few votes but would probably lose him even more against the backcloth of the electorate turning so strongly against the EU and the Euro.
Could be the final nail in the Lib Dem coffin - could win him back a little respect in the 'ivory tower left' strongholds.
In my view, abandoning Cameron when he has just had a surge of popularity would be perilous in the extreme. Still - you can never underestimate the basic stupidity of Lib Dem politicians! So ....
And of course, would he want to precipitate a General Election? - Hardly but ...