GSPlayer is definately worth looking at, and it's free.
http://www.freewareppc.com/multimedia/gsplayer.shtml
MPEG audio to include MP3's, MP2's, Shoutcast Streams, OGG, and pretty much everything else I've thrown at it thus far.
I stream shoutcast playlists from
www.shoutcast.com through WiFi. You can either save the playlists or you can go through the website and play them from there (the drawback of doing it that way is that their site is not set up for mobile devices).
As far as TV, you should look through some of the other forums, I haven't had time to get that deep into yet but plan to soon, there are also several ways to copy DVD or other format video to PPC and watch it on the go.