I'm not worried about Chip's appearance at all. Just because he might only appear in this game doesn't mean he's necessarily a useless character. Rosalina from Super Mario Galaxy probably will make very few appearances in future Mario games, but a large portion of SMG's story (and backstory, of course) revolves around her and her spaceship, so she's fulfilled a decent purpose. I'm assuming this will be pretty much the same deal. Also, if the developing team knows what they're doing (which I'm still rather convinced they do), Chip will actually be tolerable company, and we won't have to bear what happened in SatSR again.
JEV: About the physics, I noticed the parts that were concerning you, and to me, it looks like the player is just messing up or screwing around, especially on the parts where he randomly Sonic Boosts the robots on the first half of the video. I assume he got better in the second half of the video, and I didn't see anything that really looked clunky to me, so it's probably just the way he was playing the game.
The camera looked fine in the 3D sections, but in the 2D sections, the camera seems a lot more closeup in comparison to the Genesis games, and that's not very comforting, since, even with the camera movement engine, you can't really tell what's ahead of Sonic. By the looks of it, though, it doesn't seem as if Sonic really needs to look ahead at those sections. So I'm hoping at least one of these two things: the close-up camera are only for sections where far-out view isn't necessary, or the camera distance will be toggled in the final version.