I agree completely. It ain't Floyd without Roger.
After that, it was just Pink Gilmour with a Buttload of Studio Musicians.
Actually, it was Gilmour, Wright and Mason with a bunch of studio musicians. Not bad, but not Floyd.
Well, maybe... Waters had the vision, Gilmour has the talent. I'm not saying that RW isn't talented, but he's simply not in the same league as DG. Rick Wright and Nick Mason are both terribly underated for both their contributions to Pink Floyd, and as musicians in general.
I think that The Wall concert was more than a little insulting to them, in the way that they were "replaced" (the whole band, actually... I think that Waters was saying to the audience, "you don't really know us, so here are some "imitations") on stage.
Waters has an ego the size of the wall they built on that tour. Gilmour has far less ego, but far more talent to back it up.
Mark