I've started to write a php/mysql backend for that script in a hopes to have a similar system to what you want. Mainly just messing around for a bit while i get familiar with python.
A few weeks ago i started work on a real time spider to find links to videos on webpages. You type in a url and it goes to that pages, if a link goes to a video and does not allready exsist it will get added to the database. The script then follows each link on the page that is not a video and tries to do the same thing to that page. (php)
My goal in the end is to use my media spider script to constantly bring in new media, while mods can review or reject media right from the xbox. Users can report content ect.
I like watching live streams, the biggest problem i've come accross is xbmc not wanting to stream any kind of real player file. That kills about half of the streams out there.
If your stuck waiting for a nsv script of somesort, open up Winamp and load the media player, check out the tv listings, select and Enqueue any stations you want.
In your playlist window, click the manage playlist button, and save the playlist as an m3u file. Upload it to you xbox or browse to it through a network share and you should have a list of your streams.