Now after volume 50 and all possible volume 51 chapters have been released, I think time has come to follow the tradition and start the predictions for volume 51.
My guess:
Title: "The world is starting to falter" (Chapter 501)
Chapters: 492 - 501
Cover: Handsome (Duval), Kamy, Hacchan, Pappag and Luffy riding the Bon Chari (and maybe the Tenryuubito). In the background the Mangroves with it's bubbles.
Color: bright blue
SBS Hosts: Lola and the Risky Brothers
Release: 04. September 2008
In my opinion 10 chapters again, because chapter 501 just has to be the perfect ending for the volume.