The only patch remaining to move from the plugins branch are the testsuite changes, which are waiting for review (http://gcc.gnu.org/ml/gcc-patches/2009-04/msg01238.html).
I am closing the branch for now. Any new plugin development should be done on mainline. However, we may want to reopen the branch if there is any new development that would not be ready in time for stage1/stage2. Diego.