: Thing is, a visual upgrade wouldn't change that much assuming they do exactly
: what they did in CEA: Update the assets and leave everything else alone.
: If all they change are the assets, the cinematics will largely look the
: same. The only work they did to CEA's cinematics was what... A little
: animation cleanup and slight camera angle changes? If they follow the same
: pattern, I doubt you're going to get anything that much more dramatic or
: exciting than what was there to begin with.

You must have forgotten the complaints, in the new versions of a lot of cutscenes the animation is completely different from the originals (often using mocap). Sometimes it worked out better, sometimes it didn't.
A visual upgrade could do a lot, given the reliance on bump-maps to the detriment of traditional textures. For example some ammo boxes that were perfectly readable in Halo 1 are very difficult or impossible to read in Halo 2, despite it being clear in comparison they say the same thing and have the same lettering. Plus, you know, the texture pop-in.
On a side note, I'd be interested to see if the new visuals, or even the old visuals, "clean up" environments by having objects removed that are far from the player's area but still visible if you know where to look and are even reachable sometimes-- for example, IIRC, on Regret and The Great Journey there were doors way, way out of the player area that you could nonetheless see with the sniper rifle or beam rifle (and a not insignificant amount of time was devoted to figuring out what the deal with them was, which was good for the exploration and tricking communities).