:lol yearly bump... I think this is a stellar idea... and should be done.
We probably will never see this into existence, but how cool would it be to do inventory on the fly with the stylus (instead of the battle going on while you are in the menu). I can tell you, I have been killed many times by the sewer monster (can't remember the name) because I was in my inventory.
Bring Voice Chat to the DS instead of the slow typing mechanism PSO also employed.
I think they could get a 9+ rated game IF they would tweak Phantasy Star Online Episode 1 and 2 and released it on the DS. I tell ou now, I would be hooked.
†B†V† :hat