On arduino-0021, when you go to file->open, the default directory it opens in is arduino's current working directory, not the sketchbook path. I, personally, find this kind of annoying.
Checking the source (proccessing.app.Base), however, it looks like the original default behavior of the dialog was to open in the sketchbook directory, and people found this annoying, so it was disabled.
I tried searching, but I couldn't find any discussion on why it was disabled in processing. Would arduino users find the current behavior (open the cwd by default) more annoying, or my preferred behavior (open the sketchbook directory by default)?
As far as a 'bugfix' goes, it's pretty easy, just uncomment two lines in processing.app.Base. The main question is: 'is this a bug at all'. If it is, should we be talking to the processing people about it?