The following is just me personal guesses as too updates to Apples hardware over the next 6 months or so, with a few coming on the 12th and most by the end of the year.
MacBook Pros updated to Core 2 Duos is a no brainer, though I'm not sure if they'd launch it at such and event, but still possible since it is a bit more than speed bump, and you know Steve would want to brag about his new 64-bit PowerBooks.
Also, the iMacs seem to be in the same boat processor wise, though which Core 2 Duo isn't quite as obvious of a choice. If they could fit a G5 in the form factor, it seems reasonable that they could get Conroe in there too, but Merom would let it run cooler. Considering the large gap between the Mac mini and Mac Pro, a 23" iMac would just make sense, unless the much hoped for Conroe based mid tower was released, though that a lot less likely than a 23" iMac, or even a 30" iMac, so don't hold your breath.
MacBooks, don't hold your breath, possibly price drops to get it to $999 again since Yonah prices have come down since launch, but don't expect a Core 2 Duo any time soon. The MacBook is already eating the MacBook Pro's launch due to the similar specs, so the Core 2 is likely to be the MacBook Pro advantage.
Like the MacBook, the Mac mini could see drops back down to G4 levels, and I would discount the Core Duos across the line, but again, don't look for the Core 2 Duo anytime soon.
As for iPods, I would expect the touch screen Video iPod to come out in time for the holiday season, though maybe not on the 12th. The reason being to compete with the Zune and the fact that there finally seems to be a deal about a movie store. As for the regular iPod, probably 40GB and 80GB versions at the current prices, with a slim chance at a 60GB model at $349. As for the nano, probably doubling of storage on all models(2GB, 4GB, 8GB) at the same price points. I wouldn't be surprised to see a 1GB nano at around $129 either. As for the shuffle, if it survives, 512MB at $49 and 1GB at around $79 or so.
