In an interview with PSP Fanboy, N+ creators Metanet confirmed a PSN version of N+ (recently released on Xbox 360) is definitely in the works. However, it will not appear on the service any time soon. "Yes, however due to an exclusivity clause in our XBLA contract, it may not be for a while."
A producer at Atari noted that they are excited to work on PSN in the future. He pointed out the freedom developers have to create games on the Network. "The PSN has fewer restrictions on their incoming content (likely because it's struggling to catch up to the well-established XBLA) but again, on the PSN right now the indie designer has far more freedom to create the game that they imagine, whatever the size and shape." This kind of flexibility, we hope, is what will draw new exclusive content to the Network. We can't wait.