Maxis is early with the transcript this week, and it's already been posted. Besides general gamplay questions about Superstar and (mainly) Makin' Magic, there's also quite a lot about bugs in Superstar:

"Actually, because of the way we build expansion packs, almost all expansion packs include changes to the previous ones, but we searched the BBS, and grilled all of our SimMasters to get us everything that the user community wasn't happy with, and we fixed and changed a LOT! Almost every issue reported to us we fixed. The list is too long to recite, but if you want to ask about something specifically, I'll be able to give you the thumbs up or thumbs down on it."

There's no word about a patch for Superstar, for those who do have that and don't want to buy Makin' Magic. So far it seems Makin' Magic fixed the worst problems in Superstar (which was criticised a lot in nearly all the reviews), but we'll have to wait until the first reviews to see if there aren't new bugs. Some things that have been fixed are bartender Waylon, and the "Move Objects On" problem that caused Sims to disappear. As mentioned, there's also a lot of stuff in the transcript about gameplay items. There's nothing really completely new though, except for the fact that Cassandra Goth no longer has her glasses. Maxis got rid of them to prevent confusion of Makin' Magic and Harry Potter. More of that, and a lot of other things, can be read in the full transcript.