Warn has just such a rig for most common offroad vehicles (Jeep, Suburban and all forms of trucks). The winch is bolted to a "basket" and you attach it to the front or rear receiver hitch when you need it.
Sometimes you want to winch forward and sometimes you want to winch backwards - anything to get your young ass out of trouble.
The winch is normally carried in the bed until you need it (better security and it doens't screw up your approach angle).
Another good thing is you don't have to sell your winch with the truck.
I had one on my 98 Suburban and it was a dream. We got unstuck with it a bunch of times and winched out several elk and deer (and one HUGE bear).
At present Warn does not make a front receiver hitch for the Avalanche, but it is just a matter of time.
I live near the Warn factory (Milwaukie, OR) and my Avalanche was slated for making the first prototype on April 1. We scrubbed the project because my 2500 Avalanche is remarkably different than the more common 1500 (totally different front ends).
There are probably ten 1500s for every 2500, so it makes sense for Warn to make their first front receiver hitches for the 1500 (and catch up with us heavy-duty guys later).
Yes, great idea and one that works.
One bad thing - having a bad elk down, wading through a foot of snow, grabbing a hundred pound winch out of the truck bed, waddling under the load and inserting the winch into the receiver hitch is not for the faint (or weak) at heart.
I will certainly install a Warne front receiver hitch for my 8000 lb Warn winch when they become available for the 2500. One of the best possible accessories.
Steve