From what I read in "Precision Shooting" magazine they were introduced at the 07 Shot Show.
That's probably correct as to which SHOT show they were debuted at. But sometimes, and at least partially due to SHOT being early in the year, in the case of things like "action X in stock Y as a factory option" the SHOT show premier is after units have first reached the shelf.

Heck i seem to remember Members of this board having gotten their hands on some of the first Target actions made, before the Savage website was changed to reflect their creation. I certainly remember the grousing among the non BR shooters over the announcement that the first complete rifles would be RB/LP.