I think the NASDAQ suspended the market cap rules to some extent as well. Worldspace has filed chapter 11 papers. That might have had something to do with it.
I dug up an article on the NASDAQ suspending the de-listing rules. It looks like it was a three month deal starting in late October.. I guess that means SIRI has to get their shares up above a buck by late January.
Nasdaq has suspended exchange delisting rules
Actually, it's one month after being warned to get the stock over $1.00
If they follow that rule, SIRI will have another month and will be delisted at the end of February... But if the NASDAQ counts the three months they suspended the delisting, then the stocks under a dollar will get zapped right away.