I don't think it'll work, right? I believe Juno doesn't use regular PPP for dial-up. You can't log-in without launching their app.
Hmm, I guess the only way around it is to have the Mac log-in and then share the connection over ethernet with the PS2 by turning Internet Sharing on. But that'll probably lag the hell out of any game you try to play.
anyone try it and/or succeed with something similar?