Sony announced today a bunch of new titles for its PlayStation Portable handheld game player as well as a new lilac-colored model aimed at female gamers.

The announcements of new games show that Sony is still fighting an uphill battle with the Nintendo DS, which has sold more than 90 million units compared to the PSP’s 45 million or so. The Japanese company announced the news at its annual retailer and publisher conference, Destination PlayStation, in Scottsdale, Ariz.

Among the new titles are handheld versions of console games MotorStorm, LittleBigPlanet and Rock Band. Major publishers supporting the PSP with new titles include Disney Interactive, Electronic Arts, MTV Games, Square Enix and Ubisoft among others.

With Disney, Sony will ship a Hannah Montana PSP Entertainment Pack for $199 as it goes after the female market. The pack includes a lilac-colored PSP, a Hannah Montana game from Disney, TV show videos, and other accessories. Ubisoft is also launching a new line of Petz games for the PSP, where kids can take care of pets. And Sony is launching a PSP bundle based on Ubisoft’s Assassin’s Creed PSP game later this year.

MTV Games and Harmonix will launch Rock Band Unplugged for the PSP, taking advantage of the system’s built-in Wi-Fi wireless networking. Players can log into a store to download new songs for the game. Electronic Arts is also launching a bunch of new sports games for the PSP, and Square Enix will launch Dissidia Final Fantasy in North America for the PSP.

Sony also showed off PlayStation 3 titles at the Scottsdale event, including the soon-to-be-released Killzone 2, which has outstanding graphics and has been anticipated since even before the PS 3 launch in 2006. Other new PS 3 titles coming this year include MLB ’09: The Show, MAG, Uncharted 2: Among Thieves, and God of War III. MAG should be a hoot, since it will be the first online shooting game where 256 players can fight in the same battle.

Is all of this going to help Sony? Sure. But Nintendo may still widen its lead, considering it’s launching the Nintendo DSi in the U.S. on April 5. That’s the third major upgrade for the DS, and it adds interesting capabilities that the PSP so far isn’t going to match.