Combat is NOT what D&D is about. It is roleplaying.
Ah, the old "tastes great/less filling" debate. At the very least, I would say it's 50/50 in general. Even so, what do you mean by roleplaying? Does that mean good story telling, actually trying to act/verbalize your characters, or both? If we limit roleplaying to story only, I would put it 70/30 combat to roleplay (if I really want a story, I read a novel). If by roleplay you mean acting and such ... man, I will try to be nice. 100/0
edit. And yes, exploration is vital (perhaps a sub category of story, if it's done well)
