Steve,
Last year, I added all computers and iPhones to my (auto) Sirius account for a very nominal fee.  On a Mac, looks like the program Airfoil ($25.00?) allows one to stream almost any audio, not just iTunes stuff.  As recommended in this thread, I am planning on streaming audio from my computers to my AppleTV(2)- this is connected to my BDA-1.
For those who own Airfoil, is it worth the moolah and does it work as it should?
The alternative is to add a second SiriusXM radio to the existing account- and connect this to the preamp.  
I have SiriusXM in cars, hadn't thought about in the house.  I guess any  Sirius home receiver with spdif/toslink out will work with the BDA-1.  Need to do some research.
Steve