Rob Spanton and Tom Bennellick have recently released fetproxy, an open-source replacement for gdbproxy. They reverse engineered the protocol the week before I did, and their implementation--unlike mine--acts as a replacement for gdbproxy. They also managed to get approval from Texas Instruments, which is quite neighborly indeed.
I'll be closing up my msp430fet project, which was only intended as a stop-gap until Rob and Tom were able to make their release. The final state will be a standalone C client for programming; I won't be adding support for debugging.