Winamp have this new streaming plug in for winamp that is currently in beta which supposedly allows you to stream music and video from a PC to X360 PS3 Wii and even a mobile when out and about. Details are pretty sketchy but it looks like an interesting idea, the trouble with a lot of the home consoles as entertainment hubs is they often completely fail to be interoperable with each other standards or open source stuff. For instance 360 will do music and video streaming from a pc (used to be vista only but they grudgingly added it to media extender on XP as well) how ever it will only do it in microsoft aproved formats so only WMV no divx or xvid, videolan can do a transcode to an appropriate format fairly easilly but not on the fly which makes it pretty useless. PS3 supports windows media servers but wont recognise any directorys other than the standard ones so if you have videos in anything other than MyVideos it refuses to see them ditto for pictures and mp3's anecdotally it will support divx/xvid. Wii wasn't really designed for that sort of thing so fair enough it doesn't normally support a load of stuff like that.
I've no idea how well this thing works I might look at the beta when I get home. I use Xbox media center (an free linux based streaming media server that you can get on an appropriately delimited xbox) which functions pretty well for an enthusiast type of app (made with a ripped off XDK so only available from torrent)