Here are some other external links to major discussion forums where you can learn about various histories, variations in styles and principles in Wing Chun:

TWC discussion group - with GM Cheung
Started recently by GM Cheung, apparently he personally deals with questions - you have to be a WWKFA member to join this forum...not sure if any of you guys are!

Kung Fu Magazine Online Forums
Carries a good mix of kung fu styles

Sherdog MMA Forum
A good MMA forum, lots of info on equipment and techniques

Wing Chun Kuen Encyclopedia
Ongoing site compiling lots of historical data

Southern Shaolin Kung Fu
Hung Fa Yi forum - style is very similar to TWC

Wong Shun Leung Forum
Dedicated to the late Wong Shun Leung, teacher of Bruce Lee.

Wing Chun Fight Club
For those who think they are hard enough...