Parallel GC

IIRC, there was some work being done this past summer on parallelizing GC for SMP GHC (I think that's my current record for most acronyms in one sentence). GHC 6.6 is reported as having single-threaded GC, and I'm wondering if an unforeseen technical problem might have come up with parallelization, or whether something is still in the works. Excitedly awaiting GHC's SMP GC, Chad Scherrer "Time flies like an arrow; fruit flies like a banana" -- Groucho Marx