ZP > Sirius
I've decided that Sirius has 6 months left to impress me. After that, Zune Pass will take its place. It's almost the same price and significantly more awesome, provided you have a Zune. With the Zune HD now official and coming later this year (with a multitouch OLED screen, 720p output via sold-separately dock, and an integrated HD radio) and, if properly marketed, could finally start eating away at Apple's market share in the PMP market. By then, the current Zune models will have a price drop of some sort and I'd strongly recommend looking their way if you're in the market.