NIS America is bringing ClaDun x2 to PlayStation Portable on August 30. The dungeon-based action-RPG sequel will be understandably skipping UMD in favor of a release on PlayStation Network.
Again, you'll be able to customize major elements like the appearance of your character and weapons -- always fun if you have the artistic skill (or at least enough skill to Google better designs). ClaDun x2 seems to be going for more of the same vibe overall, which is what you would expect for a game with a devoted, if smaller-scale, following.
Also, writing this post just reminded me that I totally impulse bought ClaDun: This is an RPG!, played it for an hour, and have yet to see my PSP ever since. Oddly enough, I don't regret the purchase. More power to you for continuing to put titles like these out, NIS.