Rock Band Network song programming tools, turning your heartfelt ballads into batches of multicolored gems, you'll be able to place your work in front of an audience for the first time today. Harmonix is launching an open beta of the platform at some point this evening, which will allow musicians with an XNA Creators Club membership to publish their songs, and peer-review the work their fellow artists have contributed.
Of course, we won't be able to download the songs until the platform officially goes live -- which Harmonix recently informed Destructoid wouldn't be until "we accrue a good base of content, though we're already really excited by what we have in the pipeline." If you were curious about what that pipeline currently looks like, we suggest checking out this Harmonix forum post, which compiles all the bands who've shown interest in Rock Band-ing their ditties.
Update: Okay, the beta is actually live now! Let the rocking commence.