In between orders of Texas Instruments Launchpads evaluation boards from Mouser or Newark, don’t forget that TI has a free sample program that can get you a couple free MSP430 chips of varying models. Combine the raw chips with the ability to power and run MSP430’s off the red Launchpad board, and you can have quite the small army of animation and automation circtuis deployed on your layout in no time and very low cost!
Just please remember to keep TI interested in manufacturing the MSP430 processors by actually buying a few now and then. I think that if the hobby of model railroading can provide a significant enough demand for the MSP430 line of microprocessors, then we could help keep the prices low and increase the online support for the Launchpad based chips. Currently, there far more resources for the Arduino. Some of which can be ported to the Launchpad, some cannot.