I think that is a fantastic idea. He doesn't really need to be in Episode II at all. Maybe just the scenes at the beginning of the film at Padme's apartment or whatever. And if Ady keeps some sort of celebration at the end of TPM, 3P0 could be added standing with everyone at the end.

Also, I was thinking about something; does anyone else dislike the idea of Padawan's having a braid and pony tail? I have always hated it ever since I first saw them. It would probably be a hassle to do, but I would like it if the pony tail and braid could be removed from Obi Wan (TPM), Anakin (AOTC), and the younglings (AOTC, ROTS). There's probably other padawan's but I havn't noticed any. I mean, doesn't it seem kind of ridicules? The braid can be tolerated I guess, but a random pony tail sticking out? That's just stupid, lol.