I looked up some stuff about Sametime and it really doesn't look like there's much except some plugins available for Gaim/Kopete/etc... don't see it happening. Sorry, man.

As for the video center feeds, it appears that it's working. http://www.jablet.net/videocenter/test.html has a quick sample Video Center feed (Diggnation small xvid) which should work fine when the link is clicked on. It should ask you if you'd like to launch Video Center and then proceed with adding the service.

Give it a shot, you know you want to.

Because the feed format is pretty standard, I could easily see feed creation being automated by a web frontend open to our users so that they can add their own feeds and, after being tested and approved by someone (a mod, myself, whatever), being shown publically.

EDIT: RSS feed for the video center database would be perfect, allowing people to directly be notified of new shows/services added and also allow them to add the service directly from the RSS feed reader on the tablet without needing to visit the site first.