According to this, Microsoft's turned down Cave's insane top-down shooters for XBLA in Japan. According to a statement from Cave:
"Our initial plan was to port lots of good arcade titles to XBLA. We talked to IP holders of these titles, and persuaded them. We secured these licenses, and finally talked with Microsoft. There they rejected all of our proposals saying, 'We are going to cut down faithful arcade ports.' We felt so frustrated. We wanted to show them that their decision was wrong. So we switched our two most promising projects into retail."
Cave's Ketsui and DoDonPachi Dai Ou Jou Black Label were supposed to be released on the service in Japan later this year. And now they're not. So that... sucks.