I would add a 28 pin DIP socket for the processor chip to the list. That would allow you to remove the chip and install it on a standard Arduino board for reprogramming, otherwise you will need to install ICSP pins or serial connections in your standalone construction. The odds are that some bugs will be discovered late in the project or new software functions will be desired or required, so don't assume that the chip will never have to be reprogrammed.
VERY good point... I will certainly add a socket to the list.
It does take very little to build a standalone 168/329 chip to a project and frees up your Arduino board for further development on new projects.
And this is pretty much the point. Now that issue #146 has been fixed (in lastest svn revision) I can finally put the finishing touches on my pan-tilt application, but I would never want to be without a dev board to continue to play with 