sqiddster, I'd argue that video playback is a very important feature for modern games.
Just yesterday I was watching Myst's co-creator Robyn Miller do a post-mortem on Myst from GDC, and he said that when Quicktime was released about halfway through the development of the game, it changed their project significantly for the better.
Bit of an arbitrary example, but my point is that some developers might find video playback to be critical to their game, or it might open up new possibilities, and it's certainly the kind of feature that wouldn't hurt to have, especially for those of us looking more towards desktop than browser-based as launch platforms.
And, yes, I'm aware of the plugin - this post is purely in support of an integrated solution and in favour of this thread.