I love my D90. I just upgraded from a D50 and it's been awesome so far and does everything I need it to do. I wouldn't buy it based that it does HD movie, buy it for the camera and the HD movie is just a nice plus to mess around with.
It does seem a lot of people have gone Canon though recently, don't really know why. I already have various lens for Nikon so I'm probably staying there for a long time though.