Yikes, can't believe I missed this! I was literally sitting down this evening to WRITE this application (and probably base on most of Casey's MCPC stuff) then I figured I'd Google for it first.
I loves my XM Radio, and I listen to it constantly. I particularly like that I can jump out of the car and log into http://www.xmradio.com and keep listening over a web stream.
Now that Mo's home with the baby, I wanted her to be able to enjoy XM, so I figured I'd get a new Receiver with XM built-in to replace the old $99 Sony from 1996 we have.
However, since this HTML-based app works with Media Center, it works over Xbox 360. Yes, folks, XM Satellite Radio over Xbox 360. Say what you want, but I'm impressed. My digital life is coming together and it's happening on my Xbox 360. I know that gushes, but the WAF (Wife Acceptance Factor) for the Xbox purchase is now very high. She can happily listen to Ngoma (the African channel for XM that is only available online) at home!
Slightly funny note, the installer says "C:\Program Files\Default Company Name\XMRadio for Media Center\."
I hope XM realizes how cool this integration is and continues to support it.
UPDATE #2: Be sure to read the complete (technical) description on how the MCML (Media Center Markup Language) remotes the main UI. The main Xbox360 Media Center screen is render locally - it doesn't use Remote Desktop. This article also talks about how Vista will make the Xbox 360 Extender experience even better.
UPDATE: The good and valid question of (paraphrasing) "so what?" was brought up in the comments, here's my answer:
XM radio is (basically) protected content. Typically you need a hardware decoder installed in your car. However, if you're a subscriber, you can sign into their protected website that attaches you to live Windows Media streams; everything is behind passwords, etc. You can't just connect in for two reasons - Xbox 360 does NOT support random web browsing, it only supports MCE apps and you can't tell the 360 to connect to arbitrary streaming URLs. I was going to write my *own* MCE app to front all this password and streaming schmutz, but turns out they did it in 2004. The good/interesting thing is that this little app isn't widely advertised and that not only does it work on MCE2005R2 but the whole streams to the Xbox 360. What's significant is that, A. I'm consistantly impressed that the Xbox's remoted UI is so close to the actual MCE (indistinguishable) UI and B. Its nice that XM Radio thought to create one of these even if it's simple and C. The fact that I pay one subscription for XM and the content is provided to me in 3 ways shows (to me) that XM is more than just "in my car."