I've been following this for awhile... pretty fascinating stuff, and I do think you'll see at least one team (maybe two) in LA in the next 2-3 years. I don't think all of the teams listed in the poll are serious candidates to move (the Rams aren't going anywhere), but there certainly is no shortage of teams in crappy situations.
I'd put my money on Jacksonville. I think the NFL recognizes that they chose the wrong city for expansion and they aren't going to put up a fight to keep the Jags there. They don't have much of a following even when they're playing well, and their stadium isn't nice enough to generate revenue but not crappy enough to build a new one.
As far as the Vikings go, I actually think the Metrodome collapse makes it more likely that a new stadium will be built and the Vikings will stay. They have one of the most passionate followings in the league and a long tradition. I live up here, and when the Metrodome collapsed it feels like there was a sense of "enough's enough, time to build a stadium that doesn't embarrass the state and the franchise." We'll see.
Oh, and just to clarify-- the plan that Fry2Ferentz posted is from a different group that wants to build a stadium in the suburbs. Both groups are privately funded.