VCs need to work with the team, need to have faith in the team, and need to have a sense that the ideas will come. The current idea is a good start, and an indication, but in the grander scheme of things, it's the team that reall counts. They're the ones that will make things work.
A good team with an awesome idea is not investable.
An awesome team with a good idea, is.
David Hornik (August Capital; Ventureblog) basically says this also: http://www.youtube.com/watch?v=LwY0ac5XI_0
And, the truth is, A teams usually don't have B or C ideas, because they recognize, "Gee. We're looking at this thing. It's an interesting market. We have an idea. A particular approach." And, maybe it's an A-minus idea. Maybe you say, "Well, I'm not sure how that's going to evolve, but it'll probably evolve in an interesting way with this team," then I'm happy to invest and see how it goes, because, historically what's happened is they've figured out that there was some other twist, or there was a better market, or there was a better way to get to a group of people.
And so I would always start with the people, first.
It's so weird for people to base VC investments purely on "the team" -- I've always figured (as I gradully ramp my startup to my full time job) -- its great to have a great team -- and you know what else helps? having a fucking awesome idea.