Wasn't the ECL of these characters 15? So any encounter that we get XP from (+30) would be quite a nifty amount of XP indeed.
We're technically ECL 27 (12 levels + 15 LA from the free Paragon template), but thanks to the triple gestalt, we're technically CR 30 creatures. It's probably better to assume that we count as ECL 30 as well, for the purpose of experience point gain.
By the way, Zaer, do you have an idea of how powerful you want beings like the gods to be in this campaign? I will admit that I'm kind of hoping that they'd get custom stat blocks placing them at around the level of the writeups for Tiamat and Bahamut in the Manual of the Planes (both CR 25 encounters), or the stat blocks for the demon lords and archdevils in the Fiendish Codex booklets. Essentially, big enough to pose something of a threat (particularly when surrounded by their legions of followers, so we can't just waltz into a divine realm and become godslayers), but not likely to directly kill any of us off without a whole lot of luck involved.
Edit: Actually, Tiamat and Bahamut would probably be a good yardstick for a game like this one, since they're supposed to be greater draconic deities themselves. Give them more magic items as part of their hoards, some sort of home field advantage for confronting them in their homes, and surround them with hordes of their draconic and outsider followers, and they'd make for pretty challenging encounters. ^^