"Disgaea 2 is being ported for the PSP. You already know this. Right after we caught the announcement from Nippon Ichi’s head office in Japan I asked NIS America if they had any plans to bring it to us. Nao Zook, Marketing Coordinator, told us, “Well, at this moment, all I can say is that we won’t disappoint our fans who are waiting for Disgaea 2 PSP :-).” Infer what you want from the smiley face.
Disgaea 2 Portable tacks on a bunch of new content not found in the PS2 game like a whole scenario starring Axel, the Dark Hero.
No Disgaea port is complete without a few cameos. Disgaea 2 Portable adds at least Lord Zetta (Makai Kingdom), Prier (La Pucelle Tactics), and Mid Boss to Adell’s team.
As we mentioned before the magichange system where monsters can transform into weapons from Disgaea 3 is also part of Disgaea 2 Portable.
Also it looks like Disgaea 2 Portable, well at least this version of it, may not have any multiplayer features. A quick glance on the Japanese page says the game only supports one player.
You may not be aware of this, but there are actually two versions of Disgaea: Afternoon of Darkness in Japan. Originally, the Disgaea PSP port did not have a multiplayer feature. A year later Nippon Ichi re-released it with multiplayer as budget version of Disgaea Portable. NIS America spared us this fate and just released the multiplayer ready version of Disgaea: Afternoon of Darkness. This delayed the domestic release about a year, but at least we didn’t have to buy the game twice. Perhaps, the same thing will happen with Disgaea 2 Portable?"