Every few years, the rumor mill perks up with talk, speculation, or simply hope that Apple and Sirius will team up and put Sirius content on the iPod.
It ain't gonna happen folks. At least not any time soon. And the reason is simple: Apple makes money selling music on the iTunes store. Until Apple has a subscription model of their own to use, they certainly aren't going to cut into their a la carte business by using someone *else's* subscription model.
At least that's my take on it. Tell me I'm wrong. I dare ya. ;-)