This according to Forbes after BofA Analyst Jonathan Jacoby wrote in today's research note:

"The FCC issue could be more pervasive than previously believed. We believe that XM and Sirius could temporarily suspend retail shipments of certain radios, but the fix would be relatively quick and inexpensive and likely would not lead to stock-outs at retail."

According to Jacoby, the simple addition of a 25-cent part could put the receivers back into FCC compliance and a new product could begin shipping again within 30 to 60 days. "If that is the case, we believe the retail channel would remain sufficiently stocked to maintain a normal level of unit sales -- and sub numbers would not be impacted," he said.
 

[Forbes]