-Current built with clang as default + ports

[AN]

Can anyone comment on current built with clang as default compiler and 
ports?  Are there any major problems, programs that don't run?  Specifically, I am 
interested in how Gnome and Xorg (Gnome and Xorg built with default 
system gcc) work on world built with clang.


I believe the work around for ports that don't build with clang is to put 
USE_GCC=4.7+ in the port makefile, is this correct?  Any comments would be 
appreciated, thanks in advance.