I recently purchased a PN50C680 and run it along with a PS3 for my BD player and streaming content. This TV actually is DLNA compatible using AllShare and has a wired ethernet port built in (just no apps). I've found that using the PS3 is a better choice though because I like the interface better, and from what I can tell it has support for more video formats (maybe I just don't have my PS3 media server configured correctly).
In short, the TV's built in features are probably not going to benefit you much if you have XBMC or a PS3. Hope this helps, even though the thread is old. I didn't have much luck finding a lot of info on this set but bought it anyway and am happy so far, so I thought I would add to this.