I sure I know the answer to this but I just wanted to double check. I cannot find a single MSP430 that would be able to run from a fully charged Li-Ion (4.2V). Since the big marketing push is how these are low power how could it be that you must add a regulator in every design if you want to run from a battery?
Sorry to say but my next project may have to use an Atmel ATtiny processor instead of a MSP430.