So, a new trailer has been released:
here. (Am I correct in thinking that there's no way to embed videos on this forum?)
I've been hopeful about this 20th Anniversary Edition (indeed, I said so just above, I believe :P), and I think that I'm more so now:
The music sounds excellent (as is to be expected, given that--if I recall correctly--Robert Holmes is once again directing it), the backdrops remain lovely, and I really like what I've heard of the voice-acting in this trailer. The graphic-novel cutscenes look great (I'm a fan of Phoenix Online's in this respect: I think that they have some very good 2D artists).
The 3D animations are a little tricky for me to judge in such short clips, but I
think that they look better than I recall from Cognition; they're still perhaps the weakest element, but as far as I see, they look good enough.
Speaking--pun intended--of the voice acting, given the new actors the voices aren't as they were in the original. However, I do like them (more, I think, than I did the voice-acting in Gabriel Knight 2), and they sound right to me.
Overall: I'm excited for this! ^_^