The patch came out today in Japan!
After you apply the patch, there's a new title screen, with the main menu as follows:
-Arcade Battle
-Ghost Battle
-Vs. Battle
-Online Battle
-Survival
-Practice
-Gallery
-Options
So now the game feels FAR more complete; the patch basically changes the game from the arcade version into the PSP version (although it's missing the dojo mode, we get online in its place). All of the backgrounds from Tekken 5 (with their BGMs) are selectable now, too. I haven't tried online yet, but am about to...
Also, you cannot buy this patch if you got TK5 DR by game sharing! The system recognizes if you bought the game or not. I doubt you'll be able to share the game post-patch, either, but you never know.