moco

i was in the dealer today taking in the new f150 sales pitch. there's a thing about the 'hub disconnect', where some components that typically keep spinning in 2wd, no longer do so. its a pretty good feature for me as i tow alot, but only use the 4wd rarely.
the claim was that this is exclusive to ford, what i'd like to know if its new for '09, or has it been around a while?