Cain isn't going to win the nomination. If it came down to a battle between Cain and Romney, I think too many people might really like Cain but would think winning the nomination (and especially the General) would be too unrealistic. They'd end up going with Romney.
admittedly, I haven't watched the debates, so I don't really know how Cain is performing under the lights....but, if Cain (who at least has a plan) out debates Romney (who is halfway slick but never really says anything), I think Cain would trounce Romney.
Romney's only path to the nomination is by default: 1) every conservative GOP candidate disqualifies him/herself (which all have, with the current exception of Cain), 2) no one else enters the race...
This is spot on! Except I would say that Newt hasn't disqualified himself yet!
Newt hasn't disqualified himself through anything that he's done in his actual campaign, but there are still things about Newt that make him (or should make him IMO) a hard sell.