For those that are interested in experimenting with the 28 pin versions of the PIC32MX I have created a breadboard layout, ChipKIT BB32, http://chipkit.net/chipkit-bb32/ that works with MPIDE and its Libraries. It forms the basis of a series of esoteric examples, that I am working on on my blog http://caroper.blogspot.com, to highlight features of the ChipKIT that are hard or Impossible to do with the Arduino.
It is also intended to facilitate development and testing of your application in one convenient small footprint and when the application works you just swap out the Device with a blank one (available from Microchip with the Bootloader pre installed) and drop the Programmed Device into your target hardware.
As Bill said, it is a great Hobby Processor, especially now that it comes with a bootloader installed.
Cheers
Chris