I'm WAY late for this thread, but the whole debate thus far was summed up best in a book called NIGHT COMES TO THE CRETACEOUS. The evidence for both the K-T Impact AND Dinosaur extinction being at the end of the Cretaceous (rather than at an earlier point) is overwhelming. Gerta Keller is one of only a handful of scientists remaining who's made a career out taking the contrarian view. The portrait of her in the book mentioned above (or at least the depiction of her as an ethical scientist) is not flattering. While I won't judge someone on secondhand information, her track record has not been good in those areas I've been able to check.
Just thought I'd add my 2 cents as you might find that book interesting. :-)
The evidence for both the K-T Impact AND Dinosaur extinction being at the end of the Cretaceous (rather than at an earlier point) is overwhelming.Indeed, but I'm part of the lunatic fringe that believes bolide impacts were responsible for the formation of the Deccan Traps...thus sealing the fate of the dinos either by the impact itself, or the atmospheric changes associated with extensive volcanism.