No specific emulator (but Qemu works for generic ARM programs, and Scratchbox is a dream to work with if you can get it set up; I toyed around with the idea of writing a specific extension to Qemu for Chumby development as has been done with the Neo 1492 "OpenMoko" phone, but it's a lot of work and the beta Chumby's complete hardware specification hasn't been released yet), and you can get to the console just by enabling the SSH server (which is described on the Wiki and in several threads here), and doing "ssh chumbies.ip.address -l root".
For compiling your programs to run on the Chumby, a toolchain is also located on the Wiki. (assuming you have a machine running any reasonably recent Linux distribution). Hope that's enough to get you started.