It looks like Worldspace has been shut down for good.
For starters, Worldspace has been delisted from NASDAQ, it is now currently on Pink Sheets "WRSPQ.PK" and it is as of the time of this writing at 0.07 (at 29.86% loss so far for the day) with a measly $3M market cap.
Lastly, 1worldspace.com has been shut down. When you try to go there, you get a 403 error.
R.I.P. Worldspace Satellite Radio
Oh yeah, and they have already filed for Chapter 11 bankruptcy.
Their pink sheets stock plummeted by 56.25% today. The stock is now worth a measly 0.03 with a 1.5 M market cap. I just get the feeling that the company will be shut down (or bought out if anyone is willing to take the risk) by the end of the year. Hopefully it's the latter.
You also mentioned how this would affect SIRIUS. Well, they closed at 0.34 today with a 1.07 B market cap. It doesn't look pretty, but it seems to be remaining steady in the .30's-.40's for the past two weeks. But I would only half-agree with your statement. It's a good forecast of what could happen to SIRIUS XM if they don't get their shit together, but SIRIUS XM still has plenty of time to fix their problems before facing the same fate as WorldSpace (that is, if they don't get delisted by NASDAQ. But they at least have the minimum $50 M market cap and then some).
... and you're right, the WorldSpace site wasn't taken down. Apparently the website has been experiencing an abnormal rush of traffic with the announcement of the Chapter 11 bankruptcy announcement and the delisting from NASDAQ and it has caused the site to lock up for periods of time.