According to NokiaMobileBlog, a "well respected retailer" tagged the estimated arrival of the N97 into its catalog as May 31. The last report on the N97's imminent arrival tagged June 2.
Elsewhere, the official Nseries blog swears that pre-order customers will definitely get the phone the same day it gets released - whenever that is and in whatever country the orders originated in.
Man, this is like a crazy race to the finish line, what will all the smartphone announcements and launches all clustered around the same May/June timeframe. When it's over, I'm probably going to need a sedative to relax from all the excitement.