Although the flashless WGT site looks different to the one we know, all the stuff we used to have is still there, it's just hidden by a new stylesheet that WGT have added.
The messaging system is almost certainly tied up with flash, as my interest in what goes on under the hood of a webpage has lead me to believe that sending a message on here involves the use of function calls to a flash object. Not saying anymore on that as I may end up looking even more stupid, lol.
I'm sure that WGT have got plans for a new flashless messaging system, after all, they have given us a new flashless game.
As you say Marchie, logging out is one way to get back to a flashed WGT where we can send messages, and that's probably the easiest way round it.
⇩ EDIT : Thank you ada. ; ) ⇩