Congrats! Sounds like you'll be one of the first groups to take the test for FY2010. I'm not sure how long, exactly, they'll take to contact you but you'll probably have to travel to go take it.
In the meantime, if you can, I'd highly suggest purchasing this book if you don't already own it:
"Air Traffic Control Career Prep: A Comprehensive Guide to One of the Best-Paying Federal Government Careers, Including Test Preparation for the Initial ATC Exams" by Patrick Mattson.
This is probably the best book available to help you get started with the career and actually spells out what the process is like (to a degree, the process always changes though). The most important part of this book is the CD. They give you a practice exam for the AT-SAT. While it is not exactly what the AT-SAT will look like or how it will operate, it's close enough. I'd suggest picking it up and taking a look at it before you take the exam. While the FAA will tell you you do not need to study for anything, it is very helpful to have studied.
You can get the book on Amazon.com here: http://www.amazon.com/Traffic-Control-Career-Prep-Comprehensive/dp/1560276142/ref=sr_1_1?ie=UTF8&s=books&qid=1250946058&sr=8-1