I ordered 2 M4 A3's from AIM on 9/15....still waiting, although I was told on Friday it would ship soon, I'm not so sure about that. However, I've bought from aim several times in the past, rifles and ammo, never dissatisfied and never been gouged. Even got a credit one time on a late order that was not their fault. Yes, it kinda sucks that they say 2-3 weeks but that's what bushmaster says for complete rifles too, and I'll bet it's that for the standard models - the M4 A3's are in higher demand, more evil features I guess.
I'll keep my business with AIM and wait in line for my bushy. I appreciate the fact that they respected us enough to offer normal prices in this environment, unlike local dealers that are making it sound like if I don't buy their overpriced junk I'll never get a chance to buy one ever again.
It's tight everywhere in AR land...wait it out, you'll love your rifle that much more, and you'll know that you paid about $150 less than all the other guys at the range :) For me anyway, waiting 3-4 extra weeks is worth saving a day's pay.