From the Question time tonight, Miliband seemed pretty decisive about not forming coalitions. It's gutting as hell, but I get the feeling it's going to be Tories in power yet again, likely with Lib Dem at the helm. Which is weird in itself, a predominantly and historically left leaning party being the main reason the main right wing party is able to stay in power. Sigh...
Labour's plan is actually quite bold and simple.
The SNP have said they'd vote out the Tories, full stop, so Miliband is calling their bluff by effectively saying: "OK, I'm not going to give you anything, not a single concession or point of negotiation, vote me down if you like".
This gets him out of the apparently toxic accusations of a Labour/SNP coalition or any talks of a deal, and puts the heat back on the SNP to follow through with their anti-Tory position.
Will it work? It's definitely a gamble, and it's still 'relying' on the SNP, but it certainly gives Ed plausible deniability.
Tory / Lib Dem Mk.2 is a non-starter, unless the polls are utter bollocks on a whole new level.