While not a big deal for US users, having to change the paper size to the standard A4 every time you want to print is a real pain for UK and Australasian users, and 10.1 lacked an easy way to set a default. Thankfully, 10.2 includes such an option, and even tells you in the help:
Changing the default paper sizeWonderful!
To change the default paper size for all new documents, open Print Center, choose Preferences from the Print Center menu, and choose the paper size you want to use.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20020905064423159