Does Linux kernel 3.x use the CFS process scheduler?

That's still the default, yes, though I would not call it the same, as it is constantly in development. You can read how it works with links to the code at http://git.kernel.org/?p=linux/kernel/git/next/linux-next.git;a=blob;f=Documentation/scheduler/sched-design-CFS.txt

Yes, it does. It is the default scheduler in 3.x series but the kernel now has a realtime scheduler also built-in but disabled by default.

More on wikipedia: http://en.wikipedia.org/wiki/Linux_kernel