While I hope he rests in peace, and I'm sad for his family, I'd like to say.... that I never really found B.C. to be that terribly great. It might be a generational thing, but it didn't seem to be that funny. Snoopy was pretty dry at times, but there were howlers in there. Beattle Bailey, kinda simple, but it still had some laughs. The Farside, Calvin & Hobbes, brilliant stuff.
I can't think of a single B.C. that really entertained me, though.
At times, it reminded me of an old guy who says "And another thing...." 20 minutes after realizing he's lost the argument. And from a logical perspective, those cavemen both A: Seemed awful familiar with the bible even though B: The bible said they never existed. It was an odd dichotomy, especially considering the obvious depth of his religious convictions, but perhaps reading too much into a comic strip is missing the point.
I wish his family well, and I know the comic pages will be a little barer. There are plenty of new comic strips that are worth even less, and some of them will undoubtedly fill the white space.