I'm on the verge of buying it. The UI sucks and it's hard to change the playhead, but it's so awesome to be able to stream anything.
I've got the OSX beta running on my iMac with my whole iTunes library shared, even with the Lite version it's still cool having 3 episodes of Family Guy, Futurama, or South Park to watch at any given time.
I think what will finally push me over the edge is when I buy a USB TV tuner so I can stream Live TV to my phone, even on 3G and edge! (shh, nobody tell AT&T)