I wouldn't call it aggressive but I'd call it competitive, given the larger market. They could have asked $299 instead of $199 and they'd have gotten it.
Consider the GalaxyS phones which were still $199 a month ago, and the Atrix is supposed to be more phone (i.e. fingerprint security and a working GPS<G>). Sure, today there are retailers selling the GalaxyS unlocked and off contract for $199 and the cellcos are asking anywhere from a penny to $49...But that's the nature of smoke and mirrors.
I expect, or at least hope, the resellers will be asking $149 to beat AT&T's $199. Not aggressive, but not as piggypiggy as they normally are, either. For an AT&T employee, anything less than "Your firstborn and your wallet" is probably a radical concept.
Remember, they're still trying to convince us that phones which wholesale for $100-200 really cost them $600. (Don't you love the new math?!)