Printing two pages in one with Preview
In Yosemite, using Preview, I can't print anymore two pages of a PDF document on one paper, for example pages 1 AND 2 on the same page. It prints the same page (1) twice!
On the Print submenu, examine the options under Preview > Layout, then set "Pages per Sheet" to 2.
Image below from Snow Leopard, but it looks about the same in Yosemite