Field evaluations of the P-8 took place in June 2007 in Seattle, but of course there was no aircraft fielded because it hasn't been developed yet. Incidentally, production of the first P-8A for the US Navy began just over a month ago on 11 December 2007. For demonstrations etc, Boeing has leased a 737-800 for flight trials, a C-40 Clipper (military variant of the 737) for handling trials and a P-3 Orion for systems trials. The evaluation conducted was judged technically compliant by the Indian Navy.
Meanwhile, Lockheed-Martin which was eliminated from the sweepstakes has come up with a counter-proposition. Considering that the Boeing P-8 (or Airbus A319 MPA) will join service with the Indian Navy only in the next decade, Lockheed-Martin has offered to sell India a pair of P-3C Orions as a stopgap. However, going by the experience that the government had with the leasing of P-3s in the past, it's unlikely to look upon yet another sunset platform.
Insiders in the Navy say that the decision-makers are quite convinced about the convenience of operating a familiar 737 platform, and it would also involve huge savings in logistics costs. Boeing has apparently also provided a global supply chain map of how the aircraft could be used across the world, with the availability of spares and supplies assured. But I wouldn't discount Airbus just yet. They began throwing together the A319 MPA as a direct response to the P-8 proposal, and Airbus is no less familiar with the way India works. Well either way, we'll know before long who the winner is.