Last year I ended up in a world of hurt trying to find a room for Lotusphere at the last minute. (Many thanks to Francie Whitlock and Jamie Magee for helping me with that.) This year I decided to be a little more ahead of the curve and went ahead and booked my room at the Dolphin.
Earlier tonight the Swan was waitlisted, and at various times in the last two weeks both the Swan and Dolphin have been waitlisted. You may want to book your room sooner rather than later.