iPhone and Airport Express?

I understand that the upcoming iPhone is supposed to be three devices in
one - a cell phone, an iPod and a "wireless connectivity" device. I
wonder if the iPhone will be able to play music via an Airport Express?

I currently have my home stereo connected to an Airport Express, which
plays music from iTunes. I'm using an iBook to transmit the music,
which is a little awkward in the living room. It occurs to me that
playing music this way would be much more elegant with the iPhone, which
could sitting unobtrusively in a charger somewhere. However, the Apple
website doesn't say anything specific about using an iPhone with Airport
Express for this purpose. Will this feature be possible, or will we
have to wait for the "2.0" version?