If had no chance to participate in the first beta, you may have more luck now:
There is a second beta for SC2 starting on Juli, 19th 2010
All stats will be reset to let all players start on zero for the second run …
For all these, who can participate the SC2-beta, here is something, that might help you 
A downladable SC2-Beta Soundtrack. It contains:
starcraft-2-beta-soundtrack-battlenet-theme.mp3
starcraft-2-beta-soundtrack-main-theme.mp3
starcraft-2-beta-soundtrack-terran-01.mp3
starcraft-2-beta-soundtrack-terran-02.mp3
starcraft-2-beta-soundtrack-terran-03.mp3
starcraft-2-beta-soundtrack-terran-04.mp3
starcraft-2-beta-soundtrack-terran-05.mp3
starcraft-2-beta-soundtrack-zerg-01.mp3
starcraft-2-beta-soundtrack-zerg-02.mp3
starcraft-2-beta-soundtrack-zerg-03.mp3
starcraft-2-beta-soundtrack-zerg-04.mp3
starcraft-2-beta-soundtrack-zerg-05.mp3
starcraft-2-beta-soundtrack-zerg-06.mp3
Download it HERE [url=http://starcraft-2.gamersunity.de/getdl_617_12667873506179067]Download @ dl.gamersunity.de[/url]
Found here: [url=http://starcraft-2.gamersunity.de/text10885/beta-soundtrack-m-download.html]starcraft-2.gamersunity.de[/url]
Today I found a nice video, that shows the main features and ideas behind the next Battle.net by Blizzard.
Greg Canessa (Project Director of Battle.net) explains the parts of Blizzards new Battle.Net
To me, it looks like a mix of Steam and Xfire-Client 
Here it is:
[url=http://www.gametrailers.com/player/61756.html]Blizzard Entertainment – Battle.net Preview[/url]
