NOTE: This solution probably WON'T play DRM'd iPod Videos, sorry.
PROBLEM: I have been trying to get H.264 video encoded podcasts to play on my Tungsten E2 for a couple months. Even with the TCPMP player distrib, you'll get AVC/H.264 and AAC errors. Too bad, because TCPMP is an awesome free player for palm and plays most everything you throw at it.
SOLUTION: You need 2 additional plugins for TCPMP in order to play AVC/H.264 encoded podcasts (these can be hard to find):
tcpmp_aac_plugin.prc (to decode the soundtrack)
tcpmp_avc_plugin.prc (to decode the AVC/H.264 video)
INSTALL: The latest TCPMP distrib and these 2 Palm OS .PRC files, and you should be able to watch any of your favorite video podcasts (I simply copy mine to my SD Card).
LINKS:
http://corecodec.org/frs/?group_id=53
(Latest TCPMP for Palm v0.72RC1)
http://discussion.treocentral.com/showthread.php?t=101736&page=1&highlight=ipod+video
(Post #6 has the 2 attached .PRC files you'll need)

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic