First time buyer Digital SLR help?

I know for a fact that i want an SLR rather than a compact. i guess the image quality and megapixel resolution don't really matter because i'm not going to blow the image up very largely, but I want the camera to be able to take video. I'm looking at a Pentax K-x. The features seem to beat out a Canon XS in almost everyway, why are these so much less popular? First off, should i even be looking at SLRs of this quality? Leave answers or recommendations, thanks!