$320 for a gadget that isn't guaranteed to work with future OS updates doesn't make a lot of sense to me, at least if you're looking for a small music server like the Mac Mini. The price differential to get a genuine machine isn't all that large to begin with. Though it's unfortunate we'll have to wait a few more weeks for news of an updated Mini.
Plus, you don't really need the gadget. If you hunt around you can find hacked versions of the OS that one can get running on most machines without the need to buy an adapter. In particular, the MSI Wind netbook mini-laptop works surprisingly well and now has a driver for the internal wireless.