Too many advantages for Vita
Electronic Arts has apparently decided that they are opting to develop for the Sony PS Vita over the Nintendo 3DS. While they are not ruling out the possibility of 3DS titles in the future, the company thinks that the unique features of the Vita make it more attractive than the 3DS at this point.
In addition to EA, it seems to be the general feeling of most developers that we talk with that the Vita just has more going for it and a much stronger title line up at launch than the 3DS had. Many people seem to be on the fence about buying a new handheld, but the unique cell data features and the other features just seem to leave the Vita ahead of the game, even though it has yet to be released.
While some do think that Nintendo could bounce back with the 3DS, most developers believe that it will be a lot of work; and no matter what Nintendo does, they still might not be able to gain enough momentum to get the platform going again. They need more software, and with the Vita coming they just might not have the time to make it work.