Hey everyone!
P2Pool has kind of been in stasis - I'm waiting for the next Bitcoin release, which will include getmemorypool, which is necessary to include transactions in mined blocks. I've attempted to build a Windows binary, but had some trouble, and so decided to just wait (then thinking that the next release would be out soon...)
Switching the donation to be optional has been a plan for a while, and should be implemented in the next few days. It will likely turn out to be a command-line option for the percentage, defaulting to 0.5%.
Merged mining has been supported in git for a few weeks now, and we've all found a few blocks mining on the Namecoin network.
Some recent work has been done by coblee - now Litecoin is supported as a P2Pool network (currently ~100kH/s). In addition, there is a bug (possibly related to merged mining) that halts the daemon and caused a large miner to temporarily pull out.
(Sorry for not posting replies, I wasn't getting notifications.)