Just bought a D90. First impressions:
 

Just bought a D90. First impressions:
severe rolling shutter problems, some compression artifacts, ergonomics not good for video, lacking of manual controls, poor audio
BUT
fantastic colours, stunning DOF capabilities and great low light sensibilty for an incredible "cinema look".
Not yet an alternative to a good camcorder but a great tool for creative work (expecially considering the price).
I really like this camera.

So would you recommend that others buy it? Is it good enough as a tool for creative work right now, or is it too problematic and better to wait for something better? I'm seriously considering buying this camera, but I'm just not sure about it...

I would buy a D90 for its qualities as a still camera. Have you looked at Canon and Sony single chip camcorders? Very nice and very small.

There are plenty of clips and reviews of teh D90 video feature. Why not look for yourself and decide if the quality is good enough for your purposes?

The D90 is very nice, in my opinion, but it's not a camcorder. If your purpose is working on HD video, you obviously need a HD camcorder first. As "special tool", yes I think the D90 could give you a surprising creative contribution.