This is big news. TI recently open sourced it’s Boot Strap Loader for the MSP430. This allows you to write custom a host/PC side firmware downloader for your MSP430(also Launchpad!). If you wish to upgrade an MSP430 in the field, there is no need to have CCS installed. All you need is a small PC app. The PC side application can be setup in VS2010 and is based on Boost Libraries and HID Api.
You can find the entire library on github with command set documentation for the host. The wiki has examples with code for the MSP430. A Launchpad-Based MSP430 UART BSL Interface example is also up along with related code.