Bans from PSN (assuming they can tell whether you're running Homebrew/pirate software or not) isn't going to make any difference at all. The reason why bans on Xbox LIVE work is because they ban the console's Mac address. Geohot and anyone else with the knowledge of these things can spoof Mac addresses now that the Master Key has been obtained as far as I know...otherwise he wouldn't have displayed his IP address and Mac address on the video he released. They say that once the door has been opened it's very difficult for platform holders to close it again successfully...but the door hasn't just been opened, it's been opened with a valid key that can't be changed via an update of any kind.