Quoting Kyle Girard <k...@kdmanalytics.com>:
Would it be a lot faster/easier to create a custom gcc that has my plug-in compiled in directly for the windows platform?
Depends on how many plugins you use. The distgcc page says it's reported to work on cygwin. So you could use a cygwin distgcc to send the compile job to some other machine, or a virtual machine on the same machine, which runs a Unix or GNU system with elf object format.