Instead, Harmonix partnered with JRockRevolution to poll that site's users about the Japanese rock bands they'd most like to see added to Rock Band. The GazettE topped the list, followed by Dir en Grey and X Japan (whose "I.V." was included in Rock Band 2's free bonus DLC). J-rock poster boy and ancient vampire Gackt came in at No. 5.
Presumably, these bands are being considered for DLC for the existing Rock Band games, which seems like twisting the knife a bit. Imagine if you were in Japan, waiting for Rock Band, and you read that all your favorite songs were going to be downloadable in the American version.