I'm confident the Democrats will win in 2008, but I hope it isn't with Hillary. It's rather amusing to hear people call her an ultra-leftist, when in reality she has no interest in liberal issues like workers' rights and economic justice. She began as a corporate lawyer and that's still where her heart is, and she pushes gun control, bans on violent video games and explicit music, etc., to paint herself as a do-gooder to mindless suburbanites. If she wins it'll be business as usual for the outsourcers and "free trade" economic hitmen.
Obama is very unlikely as a candidate; he makes a nice political soundbite but there's no real substance to him and the media will forget him by election time. And whoever the candidate is, I doubt that gun control will be one of their big priorities. The AWB single-handedly destroyed the Democratic majority and cost the party a staggering amount of political capital in 1994. Most of the party's potential growth is with pro-gun electorates, as evidenced by upset winners like Tester and Webb. Back in the early nineties there was a big scare over militias, white supremacists and the like which fed anti-gun arguments but that's mostly evaporated now, and any political strategist with a brain knows that opposition to the RKBA is more a liability than an asset.