Dinosaur mass extinction debate

There are two posts on ScienceBlogs which highlight two perspectives on the Dinosaur mass extinction, What Wiped Out The Dinosaurs? and K-T extinction debates: cranky "skeptics" or reasonable science?. I'd assumed that the Asteroids-from-the-sky was the clear consensus, but please see this old BloggingHeads.TV clip where Peter Ward seems to imply that the waters are muddier than you'd think: