Lots of gcc work going on...
No, not much by me lately outside of darwin maintenance for Apple, but some interesting stuff anyhow:
Mem-SSA: Diego's work here is finally merged with mainline
Dataflow branch: Kenny Zadeck's work along with a cast of others (Daniel Berlin, Seongbae Park, Codesourcery)
gimple-tuples, out-of-ssa: memory savings, speed ups clean ups done by Aldy and Andrew
IPA: Jan is merging the IPA branch stuff
autovectorization: as always... the group in haifa is doing great work here
loop optimizations: zdenek's work here rewriting things
and more coming... I'll see if I can write information up on each of these.