when you pick in the direction of the string that you're going to hit, even if it's a scale, I think it's sweeping, or maybe I'm wrong...
Usually, sweeping is associated with Malmsteemlike arpeggios, but I have heard steve Vai refering to the type of picking you are describing as sweeping.
Or maybe he was in the middle of a 30 day fast, and wasn't making sense...

Chris, in your technique, is it your forearm moving or your biceps???