The code I posted here uses 4-wheel independent swerve drive. We also use the magnetic encoders from US digital.
I wouldn't try to directly implement our Swerve class for a few reasons:
1) There are a lot of specific functions and driving modes for how we wanted our robot to operate last year. This may not be how you want to operate. Look through the code to figure out what it's doing and decide if you want your robot to work that way.
2) We used the HOTPID last year, and I've not included that code here. Please contact Team 67 if you would like to use their PID class instead of the PIDController in WPILib. We have switched to the PIDController this year. In fact, I think Team 67 did as well.
3) I've not included the primary class for the robot from last year that includes all the OI. If you want to check how that is handled, all of our code from last year is here:
https://github.com/FRCTeam16/TMW2012.git
The primary class is called TMW2012. Obviously there is a lot in there that isn't drivetrain releated.
4) Most importantly, there is a LOT of value in really understanding the drivetrain and the code behind it. Use what you see as a direction you might want to go, but don't get carried away with the copy/paste. It generally makes things harder in the long-run.
The Steer class is really just a calculator for the drive mode we call steer. This is something you could implement directly if you wanted. Just call the Calc4WheelTurn function and use the Gets to set the wheel speeds and positions. However, there is also a LOT of value in understanding the Trigonometry behind these calcs. We calculate things a little differently than a lot of teams because we like to be able to turn about different points within the robot (variable A in the Steer Class) depending on the situation. All other steering code I have seen assumes a turn about the center of the robot.
I apologize for the wall of text. Got a little carried away with the answer. Hope this helps. Feel free to contact me if you have any questions.
P.S. Got your email. I have forwarded it to one of our students. He should be in touch in the next couple of days. Let me know if you don't hear from him (I'm looking at you JTN).