Yep--Blizzard is famous in part for making astonishingly good cinematic sequences. The final sequence in Starcraft: Brood War is one of the most emotionally effective scenes I've witnessed in a space opera, including any on television or silver screen. And their other sequences ain't half bad, either.
Game designers, going back at least as far as Mechwarrior II in the early nineties, have had prerendered cinematic sequences. When these are done well, I far prefer them to in-engine cutscenes: they're purtier, and that's important.
Part of the point to this is to give you an image of what the game is trying to represent. While the game itself is pretty, it certainly doesn't look cinematic in the way that the intro sequence does. The intro sequence just helps you imagine a little bit of what the game graphics are representing. If that makes sense.
Daniel