These are the current tier listings for Persona 4 Arena in the arcades running version 1.02 which will be the console release version.
Tier list discussion informatino gathered together from P4U BBS: http://jbbs.livedoor.jp/game/52991/
The placing of characters in each group do not really have any specific order so take it with a grain of salt regarding characters that are frequently used and those that are not as frequently used.
7/23/2012 – General pre-console release list
S: Aegis, Mitsuru
A: Teddie/Kuma, Akihiko, Yu, Yosuke, Chie
B: S.Labrys, Labrys, Yukiko, Kanji, Naoto, Elizabeth
8/22/2012 – Jiyuna’s “Opinions from Japan Scene” Tier List, no order
S: Aigis, Yu
A: Chie, Teddie
B: Yosuke, Kanji, Yukiko, Naoto, Labrys, Elizabeth, Akihiko, S. Labrys,
Channels of interest for your Persona 4 Arena viewing pleasure to see these characters in action pre-release