The behavior is subtle and takes some getting used to:

Stroke the Tab key once OR MORE while holding the Command key down
The application change will occur when you RELEASE the Command key rather than each time you stroke the Tab key.

Put the Dock in view, start several apps and then try the instructions above while watching the dock. You'll soon get the hang of it.

right. it always has. but i want to switch the default app switching combo to control + tab, and there's no easy way to do it (like there was in OS 8.5-9.x).

i guess i'll poke around in 10.2 when i get it tomorrow and report back.

It hasn't "always worked" at all. See the start of this thread. It used to work in a useless "cycle through everything" manner. Now it does something much more sensible IMHO.