First of all thanks to everyone so far. I'm glad there is at least a little ambiguity and the answer isn't as simple as it sounds.

Here's my (somewhat fuzzy) logic for not raising in EP with AA IN LIMIT HE. . (Both EP and Limit are very important distinctions) In NL, not raising is just down right stupid (excluding traps) because all of your money is on the line at any one time.
But (if I'm right), the NL mentallity to high pairs has been applied to Limit too often\uniformly.

With AA (before the flop) you are ahead. It's that simple. You're primary objective is to have as much money in the pot from as many players as possible. [I'm sticking to my guns on equity increasing with #players.] You make money in poker from other people's mistakes. It is a mistake for any player to put money in the pot against AA. It then would make sense to put opponents in this situation as often as possible - hence, no raise.

Call - Worst case scenario, 8 limpers. (You're still ahead through increased equity.)
Call - Best case scenario, Button raises, you three bet, 7 callers Button caps everyone calls. (not unlikely)
Raise - Best case scenario, all fold. (Highly unlikely).
This is before the flop.

Now a lot of the reasoning I'm getting in response to my post involves after the flop play. Any decision made in this way seems counter productive.
But to address these issues (as best I can).
Yes, if anyone after the flop makes a +ev play, chances are (but not always),they are taking some of that money from you - the made hand. But once you accept the fact that letting these players in in the first place reduced your win rate, you take the good with the bad, take your 31% win rate and rake in the monster pot. [img]/images/graemlins/grin.gif[/img]

I consider this decision somewhat akin to the check\raise.
I like Doyle's (even though he would probably cringe at me using it here) reasoning for a bet "I'd rather the chance of 1 or 3 bets, than 0 or 2".
And we all know how hard it is for a player (good or bad) to not call a raise after they've already put one bet in. This again goes to putting your opponents in situations where they will make a mistakes. ie. if you raise, only bad players will call. If you call, good, as well as bad will call. Good and bad players will more likely call the three bets after putting one in and the beauty is, if they don't, you got their one bet in for free.

<font color="red"> </font> Someone shoot me down in flames before I start believing my own crap. I'm going to post this in Poker Theory as well to see what comes back.<font color="red"> </font>