Sure:
WMV 720p: WMV9 video codec - 3300 kb/s, WMA audio codec - 192 kb/s
MOV 720p: AVC1 video codec - 5700 kb/s, AAC audio codec - 128 kb/s
AVI 720p: XVID MPEG-4 video codec - 4700 kb/s, PCM audio codec - 1411 kb/s
MP4 720p: AVC1 video codec - 3300 kb/s, AAC audio - 128 kb/s
MP4 1080p: AVC1 video codec - 3700 kb/s, AAC audio - 128 kb/s
MKV (720x480): AVC1 video codec - 1600 kb/s, 2 AAC audio tracks, 2 *** subtitle tracks

It's not a problem at all, i'm actually impressed with the N900 - plays regular xvid, divx, wmv, mpeg2, youtube mp4 files no problemo... i just though i'd do some tests