Don't hold your breath. Although the 12 gauge is still catalogued on their web site, none have been made for some time now while the company works out production problems (like, how they can make money off them). The retail price of the 12 gauge was raised by some $600, but still no production. I believe that the major problem is the barrels, which must be produced in a somewhat traditional manner (thin wall, soft soldered, rust blued).
Competition such as the 20 gauge CSMC RBL would dilute Ruger profits if they did decide to build a sub gauge Gold Label (and the RBL can be had with double triggers, something that the Gold Label will never have).
It has taken a lot of work to get my GL to shoot where I am looking, but now that it does I am beginning to appreciate what Ruger has wrought. No Parker, Fox or Elsie has the handling characteristics of the GL, and none (in 12 ga.) have the light weight.
If they came out with a 20 or a 28 I would buy one. The fact is that (for the money) you can buy a nice old Birmingham boxlock in 20 gauge and have a better built, better handling gun with nicer wood and double triggers. Yes, it will take some searching to find, and yes, it will probably require you to play with the stock dimensions. It will take longer, however, to wait for a Ruger sub gauge SxS and (in my experience) you will still have to play with the stock.
Still, if you want a new, lightweight round action SxS with choke tubes, steel shot compatibility and 3 inch chambers the Ruger is the only game in town (at anywhere near the price). Even in 12 gauge it weighs the same or less than most of the available 20 gauge guns. There is nothing stopping you from shooting 7/8 oz. loads through it to achieve the same effect as a 20 gauge. There are a few used GLs on the market.
Ruger could make a set of 16 gauge barrels to go on the existing frame and no one would complain, but since the barrels seem to be the major production problem I am not holding out much hope. I just hope that they do not play around with the barrels too much, as without the thin wall tubes the GL will not be anything like the gun it is today.
Sharptail