No, I don't expect it to go well. No, I don't think the Dems have proven their case. (I don't think the Republicans have, either, but they aren't in power right now.)
And I'm with Krugman; I suspect that the next few years will bring little good. The chance was Obama and the Dems' to waste: and sure enough they wasted it. They did SOME good, of course. Health Care may well be better than nothing, as is FinReg. But only barely, and considering the outsized majorities they had, well...
In any case, the frustrating part will be if the Republicans DO win back the Senate. Because when they pass bill after bill, counting on the Dems to let them get cloture, I can guarantee all of you that neither the Dems nor the media will make a peep about the fact that the Republicans convinced all of them that a Democratic Senate needed a sixty-seat majority to pass legislation, while a Republican Senate does not.
In any case, go vote. It may or may not help. But there ARE good Dems out there; your Feingolds and Graysons and whatnot. They DO deserve your support. Even the Blue Dogs might, barely, if the alternative is one of those "Tea Partiers" snug in the pockets of the Koch brothers.
But while you vote, stop and think about how the Republicans were given up for dead two years ago. Think about what changed. And think about why.