While I've certainly not herd anything official from NIS America, IGN seems to think that the hotly anticipated PSP version of Disgaea will be getting a US release this August, as indicated in a hands-on posted this morning by Jeff Haynes over at IGN PSP. While he doesn't mention where and how he got his hands on the title, I'm assumming it was at the NIS America press party last night which unvieled several new titles coming this year from the Japanese RPG publiishers.
Though I would have been happy with a straight port, NIS has gone all out, adding in a new Etna-focused story, multiplayer battles, and customizaion options out the wazoo- custom maps, custom soundtracks, etc.