Microsoft is to hold a conference on April 6th, and a few sources, including Jeux France, are suggesting that there will be a few major game announcements for the Xbox 360. Along with the article, there is a picture attached that indicates the possible existence of a few incremental titles.
These include Sega titles Phantasy Star Universe, Virtua Fighter and Afterburner, while Namco seem to have a Tales of game in the making and Konami a 360 version of Winning Eleven (a.k.a Pro Evolution). The biggest positive with these titles for Microsoft is that a few of them may move a couple of Xbox 360 units in the stagnant Japanese region. However, the biggest potential shifter of X360 units comes from Square-Enix, a mystery title only known as "New Title" so far. The 360 is already getting Final Fantasy XI, so it remains unknown whether it will it be another Final Fantasy or something completely different.
Thankfully, April 6th is not far away and hopefully we'll learn more then.