Using the front camera or not shouldn't be mixed with using Flash video or not since they are actually different problems.

Also the fact that some services use Flash video in some of their applications doesn't necessarily mean always that you need Flash video and only that to broadcast video in such services. For instance Qik for Maemo works.

Maybe it's worth investigating further about possibilities to use ustream.tv and other web services without Flash video?

You should ask Adobe for details about the Flash video availability/quality in their upcoming releases for Linux OMAP3.