It's been a busy week or two. I just got back from acts_as_conference, which was a blast. I got to talk about "The Merge"; the talk was 50% prepared slides and 50% Q&A. I'm glad I did it that way, since the questions were (as usual) great. DHH did Q&A in the morning of the first day, and fielded some questions about the merge as well. He also took questions on a bunch of other topics ("Do you Test All the Fucking Time?" "No.").
On the Rails front, I continue to wrestle with callbacks. On the bright side, once it's all done, there will be a single, uniform callbacks interface for every callback use in the Rails codebase. That includes ActiveRecord callbacks, Dispatch callbacks, Test::Unit callbacks, and of course, before/after/around filters. Once I'm ready, all of the above will have around filters, the biggest obvious change, and they'll also all be much faster in the face of a number of callbacks.
I've completed integrating the new callbacks into Test::Unit and ActionController::Dispatcher, and am in the process of merging them into AP. However, I'm going to take a break for a few days from it and see about extracting AbstractController (I'm stuck in a rut with the integration and need to take a step back for a bit).
On another topic, we had a discussion today about how to handle http parameters when there are multiple parameters with the same name (but without ""). I should have a patch to handle this later tonight. Stay tuned!