Fast AF lost on non-usm lenses?

I'm anxiously awaiting the improved Autofocus of the Canon 7D.
Maybe I don't fully understand the improvements, but will I see much of a difference on a non-USM lens?
I have several Tamron lenses which aren't exactly speed demons.

I can't speak for the 7D, but when I put my Tamron 17-50 on my bro-in-law's 40D it is noticably faster than when on my XTI. So, there could be an improvement.

Each type of motor can only move so fast due to its design and the amount of glass it is moving. A newer body with faster AF may have an impact on how quickly that lens can lock on the subject and you would notice that, but there is a theoretical limit that would be reached where no matter how good the body is, the lens will still have a maximum focus speed.

In a nutshell, you may see some improvement in your lenses in many cases, but don't be surprised if you periodically find a lens that is AF limited due to the motor design/glass and not the camera.