From Zune.net :

This year Zune is joining forces with partners NME and XLR8R to bring great music to the acclaimed SXSW Music and Media Conference, in Austin, Texas.

With over 1,300 acts confirmed, the SXSW Festival will showcase hundreds of musical acts from around the globe on over fifty stages in downtown Austin. Besides the great selection of shows and parties, participants can also attend informative and provocative panel discussions featuring hundreds of speakers of international stature.

The announced dates for each section of the conference are:

• 9-13 March: Interactive panels
  
• 9-17 March: Film panels
  
• 14-18 March: Music panels

Zune in this year's SXSW will be featuring Thomas Dolby, electronic music pioneer:

15 March 9:00 pm at Elysium
16 March 2:00 pm at SESAC Stage Café

You can find more information and details about the conference in the SXSW site. Also about the Zune participation you can read the announcement on Zune.net .

Zune team has assigned Cesar the difficult task of partying for 4 continuous nights in Austin :)

If you want to have an idea of the artists participating, download this torrent which contains 739 MP3 files (3.1 GB). You will need a bittorrent client like μtorrent or Azureus. Read more in the Conference's Toolbox.