Video playback on the Tablet PC
My roommate just bought a Fujitsu Lifebook (P1120, very cute and light btw), which is a Transmeta-based sub-notebook with a touchscreen. Using the right software he managed to play videos (divx and the like) smoothly on the Transmeta 800MHz.
When I tried on my HP TC 1000 (which also uses a Transmeta), the video and the audio stream wouldn't be correctly synched, and the video wouldn't always be fluid. The CPU appeared to be the bottleneck as it was running very close to 100% utilization.
My solution at the time had been to re-encode my videos in Windows Media format (using Windows Media Encoder) and they would play fine. I am not sure whether the WM9 format is more efficient than the latest DivX format or Windows Media Player is just optimized for it.
Now the CPU usage is between 80 and 90%. The Tablet definitely gets warner than during browsing, but by switching the display into the "Landscape secondary" mode, the vents shoot the hot air away from you and the speakers are now un-obstructed.
He also recommended GSpot, that allows to find out what codecs are needed to play a video file. Seems pretty useful, but haven't tried it yet.
You might also want to check out the AC3Filter project, which will enable AC3 encoded sound in DivX videos.