Interesting. My countdown clocks for both Radisson and Country Inn are at five minutes and counting down. Of course 00:00 May 15th is in five minutes here in Japan. Early signup possible? We'll see.

Edited to add:
Nope. At the zero mark both sites tried to continuously redirect, the Radisson page also causing my screen to flash black and white and sending my hard drive into a frenzy. I could see the URL of where it was trying to redirect to, and if it wasn't already midnight here and me having to get up early tomorrow for work, I might've tried playing around a bit with it.