New Mac Mini

So today I finally found the time and courage to sit down and spend my J&R gift cards on a new Mac Mini.  We are going to use this for the television in the living room so the 1.8GHZ / 80GB model should suffice.  I had been sitting on this purchase for some time now (through MacWorld, etc) waiting to see if there would be a product update (also risking a rumored product discontinuation) and nothing has changed.  I’m comfortable with this purchase, however thoughtful of the fact that an update could come at any moment. I believe I heard Leo Laporte say that there was a window of time in which the recipient of a recently refreshed product could return their new old model in for a new new model.  Is this the case?  If so, how long is the window?