One thing on this, and similar questions on races (gnome, half-orc...):
It doesn't even matter what the majority thinks. The majority of potential players could care less. It matters what a minority thinks, if omission--as a class--messes with their play experience. If it does, then that omission is a serious problem for WotC. Both for the direct effect, and the network effect (this one guy in my old group doesn't like it now...)
The trend for D&D, going all the way back, is to have a fair number of classes (B/X resisted this the most...but even their there was a tendency to add some new classes). Paladin and ranger aren't even really debatable: they will be there. (as will the druid, bard and probably monk and warlord or something like it). The question is, would omitting, say the barbarian or warlock, annoy enough people as to merit inclusion in the first PHB or equivalent.