First, we heard that The Beatles: Rock Band would be released as a SingStar PS3 game with all the non-singing gameplay removed. Then Harmonix told Joystiq that it was just a potential microphone bundle for Rock Band, marketed at the SingStar-loving PAL audience.
The real bundle, as revealed by Australian retailer JB Hi-Fi, is somewhere in between, though the corrected Harmonix story was way more accurate. It's a regular copy of The Beatles: Rock Band and two SingStar mics, in a big SingStar package. JB Hi-Fi states that it will be out September 24 for $99 AUD ($86.61 US), and we have yet to see it pop up on any other retailer sites, so we don't know if it's PALexclusive or Australia exclusive, or where it'll be out. We'll check with Sony.