Win 8 will have it. Some versions of 7 have had it for years already.
Until now, I have avoided it because of a fear of complexity ..unreasonable maybe, but I'm increasingly concerned about the security of my data drives in my personal laptop and workstation systems. Especially the workstation, with it's drives all being easily removed...but also laptops sometimes grow their own legs. Or wings.
Does anybody have experience with BitLocker either in 7 or 8?