[bfoutch]

Does anyone know the specifics about what the warranty on the Outbacks OEM tire (Continental pro contact) covers?

specifically treadwear? my tires are at 37,XXX miles and the tread is nearing the end of its life... does subaru prorate a new set? or am i left high and dry?

I believe that your tires are covered by the tire manufacturer's warranty and not by Subaru. Here is a link to their warranty web page:
Continental Tire Original Equipment Tire Warranty

You can also call them at 1-800-847-3349

I have also attached a copy of the original equipment tire warranty from this web page. I am pretty sure that the best you can hope for is a pro-rated discount on a set of new tires.