Here's a small report from my try out of xbmc-12.0-Frodo_alpha7 with a bunch of stuff I have access too.
* Samsung TV PS50C7000 (known as PN50C8000 in USA) - cannot play any media but they are supported, Samsung are notorious for requiring custom profiles so not too surprising, also it cannot browse the TV show Title section it errors out saying cant retrieve playlist but it can read the files area.
* LG TV LM760T - works fine.
* PS3 - works with supported formats however there is an unusual bug where some of the text on a section disappears and turns into a hyphen (
see photo), it only happens at that level when you get down into your content or files it's fine.
* Xbox 360 - works fine with supported formats.
* Boxee Box - works fine.
* Popbox V8 - works fine.
* Various iOS UPnP/DLNA clients - works fine (mediaconnect seems the best of the bunch if you want to see coverart).
I have one suggestion, if possible maybe put a 'File Source' section at the top level alongside 'Music Library' & 'Video Library', you could also put in the photo and music file sources in there too. One of the complaints I've observed about UPnP/DLNA over the years is the menus you have to drill down to get to your content for people who just want quick file access and nothing more. Obviously you still have to have a files section in the sub sections for things like the Xbox which dont give you access to the top level.