If you choose Save As PDF from the PDF button at the bottom:

You’ll get the save dialog, with some great new features:

You can now set the title, author, subject, and keywords of a pdf file.

Even more impressive, if you click on the Security Options… button, this dialog appears:

You can password protect your pdf document, as well as set a password to copy text, images, or other content. You can also set a password to allow printing of the document.

These are all pretty cool new features that weren’t available in Tiger, and to Adobe’s chagrin, alleviate some need to buy Acrobat Professional.