John "Omega" Williams
Their potential is only exhausted when you run out of possible stories to tell. The non-location specific tiles can be anywhere.
More tiles seems to be coming as I believe there is mention of outdoor adventures and a mouse town. I would guess the outdoor part at least will get tiles.
Having in mind that the base tile set is rather exhausted, as it has already covered 3 stories (base game, downloadae scenario and latest expansion) it is high time for some additional tiles. Those locations have been doscovered already many times. Withthe upcomming "big box" expansion there should be new set of tiles in a number of at least the base game. That would give a potential for new stories or at least development of the curent line.
Looking forward for the big box!