It is probably best to book what you want and then you want be disappointed.
We stayed at the Dolphin once before and got a small upgrade to resort-view but I had heard that if you are a Starwoods member that you automatically get an upgrade? Maybe I misunderstood. We got a great rate for our trip anyway.
I can't complain. We were very lucky to get some "pixie dust" at BWI on our 30th anniversary last year.