Dude, the K10D is a sweet camera. Plenty of resolution, and the weather sealing is prime for wintertime. I liked it better than the 40D for most things (the menu's retarded, but that's something you can learn and adapt to)
Nicer APSC size sensor cameras aren't going to shoot anything all that much better..
It all matters on the lens for the most part. Pick up some Pentax SMC manual lenses and throw them on that thing. For landscapes and stuff, you'd be set. (or just get the Kmount adapter for M42 mount lenses, so you can use the extent of all that sweet vintage screwmount glass. best thing about the kmount's design is the ability for kmount to M42 and L39 screwmount adapters to give you the exact same flange focal distance).