If video is your main goal, I believe the D90 would be a more logical progression from the D80. Same size and general ergonomics with more functions and options to play with. You can use it almost as a point and shoot but with the option of controlling everything manually if you would like. And of course, you have the video in the D90 which is not great, but certainly functional and nice to play with.
I briefly had a D5000 which I returned because of conflicts with different lenses. My impressions in the short time I had it was that I was missing the versatility of the D80 and D90. The swivel screen is ok but not a big deal.