By Suzanne Barlyn NEW YORK, July 29 (Reuters) - Asian stocks were set to track an upbeat Wall Street session on Thursday after the Federal Reserve kept interest rates at ultra-low levels, while the U.S. dollar fell to a two-year low. The greenback has tumbled on expectations that the Fed will continue its ultra loose monetary policy for years to come and speculation that it will allow inflation to run higher than it has previously indicated before raising interest rates. "We'll probably see a gain of 1%...later on this morning," said CommSec market analyst Tom Piotrowski in Sydney.