There is not a larger sail rig being planned as an add on to the current Adventure. The sail is plenty large for the size and stability of the hull.
That is pretty surprising that Hobie, the sailing pro, is not planning on designing a new sail for the BigA. My guess is that it will happen eventually, but at the moment they probably have too much on their plate with all the new boats.
But other folks are already ahead (way ahead) of the curve on new Hobie sails, even for the Sport, the smallest sail-ready boat in the fleet. You can see in the pic above how puny the stock 20 1/4 sq. ft. stock Hobie sail looks on the BigA.
How about a 32 sq. foot windsurfing sail on a Sport? That really makes the Sport get up and move. It can even get up on a plane for a short distance! Punchinello, the Hobie Kayak Sailing Master has integrated just such a sail, and has used it successflly in 15-20 mph winds, along with a home-designed and built ama on his Sport. Has never capsized either.
You can read about his amazing sailing adventures with his Sport and a friend's Outback here.
http://kfs.infopop.cc/groupee/forums/a/ ... 009851/p/2
Here is a pic of his original (pre-windsurfing sail) rig.
Here is a more recent pic of the new leeboard and jib. He has also designed a new, large rudder "sleeve" for use in sailing also that slips over the stock rudder.