Is it possible to crop multiple pages in Mavericks Preview.app? Is it possible to crop multiple pages or image files in the new Mavericks Preview application just as described in this answer?

The functionality was there with Snow Leopard but disappeared in Mountain Lion.
Yes.


Open a PDF.
If not already enabled, View → Thumbnails.
Select some pages (click first then select all; command+click or shift+click)
Use the rectangle tool to select region on page. (On versions of OS X prior to 10.9, you should see a preview of the selection on other pages too).
Select Tools → Crop (or Command+K). All your selected pages should be cropped.
Save or Save As.