The fact that tours to India always seem to end up having seven ODIs and only a couple of T20s suggests that the former is more profitable: they wouldn't do it that way if they made more money with T20s. That's a big reason why you're never going to see it go completely in the short term, folk are still making money off the thing.
I prefer ODI Cricket to T20 stuff; that's probably because I like it when Cricket is a more even contest between bat and ball, and T20 definately does not have that. They shouldn't change anything in the short term; they've spent the last ten years dicking around with the format only to basically get back to what they started with; a period of stability is needed. I don't think that 40 over Cricket would work; they tried it in England for a while and the result wasn't a format that was really any better than the longer game. Besides; its the best format to use at lower levels which can't support multi-day Cricket (School Cricket; Uni Cricket; Club Cricket; most Cricket in Associate nations etc); and it makes no sense to use it there and get rid of it at the top level: that'd be like Rugby games being eleven a side at lower levels and only fifteen a side when you get into the professional game.
I've edited the thread title; it had an extra word in it that shouldn't be there and it was really annoying me