GDC release cycle

[Sjoerd Nijboer via D.gnu]

I was wondering what the schedule for the GDC release is, since 
GDC is quite a bit behind on the dlang frontend version.
Is it a release whenever a couple new major D features appear? A 
new release when there's a bugfix? Or does GDC follow GCC's 
release cycle? Even then, when does new checked-in code make it 
into the actual release?