Could that be felt in the steering wheel? Sounded like there was play in the steering wheel.
I'd have them check the preload on the bearings again. Since you said they were replaced, then the preload could change after the initial test drive. Too little preload could cause tires to wobble. Too much causes drag which will bring down your mpg. I had to monkey with mine a few times after the shop replaced my axle (WAAAY too little preload the first time).
[SIGPIC][/SIGPIC]
Put a smiley after you say that Bub.