If you prefer the Arduino form-factor, but like the 9S12C microcontroller, you will be interested to learn about Esduino12, a new product by Technological Arts. While a community project is currently underway to port the 9S12C to the Arduino Development Environment, there are plenty of other choices available now for doing software development under Windows. There is Freescale's CodeWarrior for C and assembly language development, Feaser's Eclipse front-end for GNU C, Eric Engler's AsmIDE, and nqBASIC from Technological Arts.
The Press Release about Esduino12 can be found at http://www.technologicalarts.ca/shop/component/content/article/65-products/166-what-comes-after-qrqduino.html