I recently ordered a lot of parts for a project I'm working on and the low price of the LaunchPad made adding one to my order pretty much a no-brainer. Ends up this is a very nice little board. It's definitely less 'friendly' than the Arduino but it does allow for interactive debugging with gdb. Being able to step through a program running on the mcu without extra hardware was a nice surprise.

edit: I should also mention the program mspdebug which is a little simpler than gdb. I actually didn't look at this program much after seeing it could let me use gdb but I just looked it over a bit more and it also lets you step, set breakpoints, set registers, and more.