So, well, a mostly-functioning HPPA port of SBCL has been merged, SBCL 0.7.7 has been released, tbmoore's linkage tables stuff has landed in CMUCL, Gerd Moellmann has been busily cleaning up PCL, Alexey Dejenka's nailed a few more obscure compiler bugs, and I've started reviving the MIPS backend. It mostly works, but sadly not entirely.
On the plus side, this backend is the last of the legacy ones from CMUCL that I care about (I am planning to abandon the support for the IBM RT; so sue me), so after this it should be much more fun... if refactoring compiler code can be described as fun, that is. Maybe I'll be able to help merge the wave of patches to the compiler codebase that have been rolling in recently, too, and even work on some of my blue-sky projects (loop invariants, mmm).
[ Edited to get names more correct ]