Oh and don't forget amazing western games like Dementium and Moon (15 hour long FPS title which is longer then most console FPS titles lately) Lock's Quest and Viva Pianta (MS IP imagine that). is also very good.  Advance Wars and Bleach Dark Souls is very westernish even though it's a japanese developer.  Not to mention the many western developed racing titles like Grid and Diddy Kong Racing.  There's good support from all sides on DS just so many Japanese titles overshadow western titles, but there's no excuse for not being able to find something you like on the handheld, like Call of Duty on the DS is really amazing, it's got good graphics and world at war even has good online, CoD4 on DS has good local multiplayer but no online saddens me :(

Anyway on topic, MS probably won't make a handheld cause a lot of their IPs that get put on a handheld are going to the DS and it's an easy way to make money.

Sony ruined the movie part with the bad idea of a proprietary disc that doesn't offer to users perceivable advantages over standard mini-DVD's, and let's not consider the bad idea to think people would pay to see movies on a very small screen amounts worth the producers' effort, the movie part of the business, had it started asking a more reasonable price, would have been barely profitable without the burden of a proprietary format, but for a device that would want to do everything, and we know haw bad this ends usually, and considering that it was the first Sony handheld and it had to clash against the titan of handhelds, it didn't go so bad, right now it's approaching 44million units sold. PSP is doing quite good in HW sales, although SW sales are acceptable only because the user base is large enough to give decent numbers despite a very low attach rate, and movies sales are (well, more correctly, were) a disaster. But in the end, people buy them, Sony earns money from them, it's more than MS managed to do with Zune, and a lot more of all the past handhelds that defied Nintendo and died.