I was thinking of buying an airport express with iTunes to play music all through my house but now that I have the iPhone I'm wondering if they'll upgrade a new airport express to work with the iPhone so you can move all over the place, change songs, etc... without having to go back to the computer (actually, for mac owners, telekenesis is probably the answer.... but for windows?)

any ideas?

i would say you're more likely to see an arrangement where the iphone is a complete remote controller for the apple tv which in turn would be transmitted through airtunes.

I'd say wombat is on the right track. Macrumors just posted this story which describes the possibility of using an iPod or iPhone as a remote control for your media hub.
http://www.macrumors.com/2007/07/19/...emote-control/

well, if you have the iphone, you can use RemoteBuddy to control your computer over wifi all over your house.. ;-)