The Diddy Kong banana thing isn't much of a nerf. Being unable to juggle two of them kinda sucks, but on the other hand, your opponent now has pretty much no ability to use them against you since you just down special as soon as someone grabs one to make it disappear out of their hands. So Diddy is losing some of his ability to control a lot, but he has tighter control over what he still has. IMO the general mechanical change (at least it was this way based on E3 demo reports) of glide tossing being gone hurts Diddy more than this change. Diddy's core design is pretty strong though; I imagine he'll be fine.
Pac-Man sounds kinda like G&W to me? Kinda slow and floaty with very beefy hitboxes and notably good aerials is a not so terrible description of my favorite flat man. Unlike the rest of you, I really want my characters to be very top tier and very strong so my brain is telling me to be apprehensive about Pac-Man but my heart turtle says to go for it!
Really all of this info is very interesting; I probably won't be awake for the AMA, but I'll be studying all of this in great detail. So far it really sounds like the demo build the rest of us played wasn't horribly unrepresenative of the final product, and to me, that's a great sign. Thanks a lot Zipzo for gathering this info; it sounds like you're getting in a lot of playtime and also doing the work to let people know as much as you can, and I know from my Best Buy experience that it really is a lot of work you're doing.