The polls, essentially, are telling us nothing.
The key factor isn't going to be which party is a point ahead in the final day. When they are this close, the result will be down to who gets they vote out, and where the variations are.
Labour may punch above its weight a bit because its vote may feel more motivated to ... um ... vote. The Conservative vote probably doesn't have as much reason to get out - Cameron's campaign has been rubbish and negative and no-one really likes what he's offering. The rightwing vote will fracture in some critical seats, just like the left vote did in the 80s, allowing Labour and Lib Dem wins on poor vote share.
Scotland seems mysterious and ineffable. Anything like a clean sweep seems unlikely, though the SNP will make massive gains. I think there will be a god turn out in Labour's vote, and perhaps in the recent converts to Sturgeonism, there will be a reluctance to jeopardise Labour's chances of forming a government by forcing them into an awkwardness with the SNP ... But it is just a hunch.
So, with the expectation of being proved hideously wrong, here goes ...
Labour 281 (Based on getting more of their vote out)
Conservative 274 (Right wing vote wastage due to UKIP)
SNP 40 (I just can't believe the total annihilation the polls are predicting will happen. Does. Not. Compute.)
Lib Dem 30
UKIP 2 (Big vote, no seats. Gotta love FPTP!)
Which might put Labour+ LibDems JUST within reach of a majority without the SNP, based on Sinn Fein abstaining and the SDLP voting with Labour. Greens and PC as possible additional partners.
But anything up to and including a slender Tory majority is still possible, based on just minor shifts.