I read a post that mentioned the Airport Express had a usb 2.0 port, but I didn't see this info when looking at apple's site. If it's 2.0, why? Seems like overkill for printing (although I'm sure some can point to reasons for doing this). If it's 2.0, seems like a good device to plug in to a set-top box that would have the processing power needed to decode some kinds of video streams and to display pictures (taking advantage of whatever data rate over the 11mbps of 802.11b and usb 1.1 that the combination of 802.11g and usb 2.0 could achieve - yes i know that the wireless is the limiting factor here, coming in somewhere between 20 and 54 mbps).
Alternatively, and probably more likely I suppose, apple could keep the device focused on music only and release a remote that wirelessly communicated with the originating computer. And, as others have pointed out, this could well be included in a new ipod. (Not to mention streaming from the ipod, which would be pretty fun when friends come over. Some pretty cool software solutions immediately present themselves - a party mix option that draws randomly from all available ipods...) I'd hope there would be a separate and cheaper remote, though, for those with older ipods.
I'm very curious to see where this will lead. Releasing only airtunes, with no way to control the tunes, is so obviously begging for an additional solution that it would have been clear there's more to this - even without the apparent hints apple has given.