Preview has changed a fair bit with 10.6.2, sig.
Using Preview 4 it used to ask (and there was also a "rotate all" option in the "Tools" menu, from memory), but now, under Preview 5, you need to follow the selection process mentioned
here.
There are quite a number of other related "workflow" changes too, with respect to things like combining pages into a single document (see
http://support.apple.com/kb/HT4075), electing text within columns, scanning into preview, improved screen shot capability, etc.
Most of them are really quite useful improvements. Not quite so sure about the rotation approach, though.
Cheers
Rod