Ok, before we go hog wild here, there are some potential issues with throwing every source out there up for discussion.
Spell Compendium: I don't own it, so I can't comment on it.
PHBII: Again, I don't own it, but I can borrow it readily, but have not fliped through it enough yet beyond the Knight.
Heroes of Horror: I don't own it, but I have seen the Archivist, and like it, and can probably jot down some notes so I can approve them if need be.
Races of XXX books: not all eberron flavored, so any crunch from them would have to be examined, though the Chamelion class fits well for the Changeling, and any human/dopleganger feats should be allowable to the changeling as well.
Complete Psionic: Released April 2006, which means it hasn't been out 6 months, so I'd suggest holding off on allowing it, though I think the Psionics Eratta inside is worth considering. I've not had much time to read everything in it yet though.
Keep in mind, the more source books we require, the harder my job as the character judge is (And anyone else who later joins). Right now, I can approve characters fairly quickly. Extreme expansion will eventualy increase the time probably a good tenfold.
I think we should take this a bit more slowly and in some kind of organized fashion. So, I recomend we first start with base classes and races, and move on to feats and PrCs from there.
That being said, I see strong support for the following core classes:
Scout (CV), Swashbuckler (CW), Spellthief(CV), Warlock(CA), Hexblade(CW), Spirit Shamen(CD), Archivist(HoH), Favored Soul(CD), Duskblade(PHBII), Knight(PHBII), Beguiler(PHBII), Dragon Shamen(PHBII)
The Oriental Classes have mixed acceptance, but I'm not against limiting some core classes for simplicity's sake, since there are plenty of good options out there with the above list. I understand there are a few arguements about the other classes as well, but these generaly seem to be the ones most people favor. I'm willing to allow all the ones I listed in.
I haven't heard anyone mention the Marshal. Anyone like/dislike that class?
I also see strong support for the Complete Psionic classes, but given I haven't even seen them yet beyond a quick glance, I can't realy comment on them.
I agree on the SU/Mind affecting for the Knight, but only for flavor. Mechanics wise, I don't see it as a HUGE issue, as several of the chalenges are moral bonuses for the Knight and Friends.
Races:
As I mentioned earlier, the monsterous races in the MMI and MM3 are already accepted except the subraces of the core PHB ones (with the exception of Grey Elves). Are there other races from other sources people feel so inclined to support?