The vote is split nearly 50:50 between the Millibands. This represents the underlying split beween old and new Labour.
I have thought for a long time that Labour will split with some drifting to merge with LibDems to form a new centre Left party and a hard core rump of Old Labour on the far left.
I do not think Ed will win an election though. He will be a Hague/IDS/Howard figure and another person will have to come forward to unite the party again if it ever stands a chance of winning again. I think that Lib Dems are now in a good chance now of representing the majority of the left popular vote.
I think there is every chance we will end up with a two party system (Liberal:Tory) with minority parties and especially if we have a PR system of voting.