Welcome to the Dha(r)ma Wheels, Mettafuture!
I agree that it was very clever to create this pair of Buddhist websites--in fact, it might even border on genius! Putting a firm but porous barrier in between the Theravada and Mahayana websites seems to help maintain order and reduces unnecessary conflicts.
Some people lament the fact that there is no Buddhist forum which includes all the major Buddhist traditions; however, people should realize that
Dhamma Wheel + Dharma Wheel = a forum which includes all the major Buddhist traditions!
(Okay, so you have to log in twice, big deal...)
In my experience, the members are nice on both sides of the fence.