The first UFC game for Dreamcast really did something different with the fighting genre. It felt like a very violent game of chess and always kept you on your nerves. The license really lost steam as time went on though and eventually UFC games stopped being made all together. Now that the UFC is more popular than ever, THQ has decided to bring the octagon back to gamers.
Joystiq has an article about the deal up, but let me quote the important part for PSP gamers: "The agreement will span all console and portable systems..." They didn't announce if one developer was handling all versions (which is unlikely) or if a different developer would work on each version. Judging from the huge stable of studios that work with THQ though, it's likely each platform will be a concentrated effort.