That airport express does look like a saucy bit of kit. Iphone is a control option too. Nice. But Apple schtick only.
My brother has a sonos setup & that is just great, a really good, intuitive, well sorted thing, but music only.
At risk of sounding like a record with a scratch, there is of course media centre & extenders, either an xbox, or either a Linksys Dma21 or 2200 or a Dlink DS750M. Of course both require a screen & a remote, but will stream your album collection anywhere they're hooked up.
Otoh, this could be worth a 2nd look.
Linksys announces Wireless Home Audio System, another wireless audio toy for rich people
Essentially, to receive wireless audio, you have to have a transmission point, a network & a receiver. It all comes down to the colour of your wallet & what you would like it look like.