How do I set up a Mac to use both FileVault and Boot Camp?
It is possible to use Bootcamp with the new Filevault.  The exact method of achieving this may differ depending on if you already have Filevault turned on, and want to install bootcamp, or if you already have bootcamp, and want to turn on Filevault...

Either way, you will need to ensure that you use the very latest bootcamp drivers package (4.0), which either need applying to your existing windows install or writing to CD/USB stick prior to beginning the bootcamp installer.

To check your current BootCamp level, run Boot Camp Assistant and select About from the menu bar, at the present time the current version is Version 4.0.1 (429).