I'm testing InDesign CS6 under OS X 10.8. Seems to work without problems - except one thing which I noticed several times while working on a document (that I was working on under 10.7 as well, without problems):
I transform a group of objects (mostly placed Illustrator EPS) by dragging one corner of the group (with one or more modifier keys). After a few moments InDesign gets unresponsive (it freezes, cursore won't move, although you can change apps via Alt+Tab). Activity monitor shows 100% CPU usage (for one CPU core, at least). After a few seconds, everything goes back to normal.
Process analysis looks sth like that (it goes on and on like this):
This might be a problem related to this very document. On the other hand, this worked flawlessly under 10.7. So maybe someone at Adobe wants to look into that?