We will have to see what happens, but I still think a Lib/Con pact is unlikely. The Lb/Dems are a lefty party, much further so than the Labour Party. It show your desperation that you are yearning to go into bed with them to grasp power.
Policy wise and ideoligy wise, the Lab/Dems are closer to Labour. They have previous form of working together during the last hung parliament. Then, the Liberals rebuffed Heath. History could be about to repeat itself.
In terms of what is on the table, Labour seem to be offering the Lib/dems more. Clegg only said he would listen to the Conservatives first because they had the most votes. But if he does not like what he hears, he can walk away with a clear conscious.
Brown is a lame duck. The Labour Party can get rid of him at their conference in September, if not before. That would leave Milliband (if he is leader) and Clegg to work within a minority Government. When the Lib/Dems have had their referendum on PR and Milliband has settled in, they will be in better shape for the next General Election which will be triggered long before the full term, maybe within a year.
Finally, if you look at their CVs, Mandelson (who runs the Labour Party) and Clegg, are from the same mould. They have booth worked within the EU, and both share the same values. With Mandy's powers of persuasion, Clegg will probably opt for an alliance with Labour, as people have suspected all along.
But I could be completely wrong, we shall soon see.