Do you have a bunch of Pentax lenses? If yes, just upgrade to the K7 or wait a little and see what's coming out from Photokina (September)
Personally i use a video camera for videos, i have a Canon 7D not only don't i use the video feature ...i rarely use the camera over my "entry level" Pentax K200D
MOSTLY because of weight ...my Pentax 3 lenses bag is ~1/3 the weight of my Canon 3 lenses bag
I think you might be more of a video person vs a still photographer, you need to decide and gear up accordingly.