DLNA isn't the answer
Does your device not support DLNA? My entire entertainment system does right out of the box. Whether you have Apple TV or not, your BluRay player or your TV should support DLNA.
And that's kind of redundant anyway, because if you are syncing your music through Zune, which uses Windows Libraries, just leave your PC on... Windows Libraries can be stream in their entirety to the same TV's and BluRay devices... I do it all the time.
You're kind of missing the point.
I'm in the same boat as the original poster.
*Airplay devices are not DLNA compatible.
*I don't want to leave my PC on--it's a 600W gaming system / space heater that I only turn on for gaming or sync'ing.
*I can print to an airplay enabled printer from my phone, stream music to my airplay enabled router with *two taps* (DLNA generally involves a lot more steps), throw video to my appleTV with *two taps*, and stream HD media without a problem.
*The apple TV device is about the size of a stack of square coffee coasters, is fanless, and doesn't overheat. My XBox slim gets quite hot in the AV cabinet, gets half the wifi signal of the appleTV device...in the same cabinet, has a less intuitive multimedia interface unless booted into mediacenter, and takes a bit longer to boot up.
I was a Blackberry, then WP7 user, then an Android user, and now an iPhone user. I had all the i-devices to support my wife's i-habit...and couldn't find the Windows equivalents, especially with two-tap ease of use. I love the WP interface, but it lacks the ease-of-use that airplay has...so get me airplay in two taps, and I'll sell my iPhone the day that the 920 comes out! A fanless, SSD XBox with better WiFi couldn't hurt either. or a Media PC that didn't involve more than $250 or self-construction. Or simply an XBox functioning as a media center rather than a Media Center extender (why do I have that massive HD if I can't fully use it?)