A curious fact one can learn if you actually read the article you’re sourcing:
The Rock Band Network is the result of a 16-month development process with a number of partners. Most important was Microsoft. Tracks released through the Rock Band Network will only be available at first to Xbox 360 users, as it relies on Microsoft’s XNA game development platform and its Creators Club online community of developers.
So, when I say “all of us,” of course I am referring to 360 owners. We do apologize for the confusion.