Here are two ways to convert an Apple Pages document to PDF. Neither is better than the other. Select Export to from the File menu and choose PDF. Print the document and instead of hitting the Print button select an option from the PDF pop down menu in the lower left corner of the Print dialog box. The last option is particularly useful if you want to mail someone the PDF or save it directly to a specific location (as indicated by the options).
This was a useful feature when I took my classes, and I was saving the PDF file directly to my desktop, so it would not be lost on the server when I mailed it to my students. I would still prefer the File → Export PDF option. There you have it. The one thing I love about Apple's Pages application (besides the fact that Apple is still the best company about which we have any meaningful news) is its ability to convert other formats as well. We need more applications that do this for us. I don't think Apple's Pages application will be much of a threat to Adobe's products, so they will probably continue doing that themselves, but the rest of us will love knowing we can take PDFs and use them with any other software we have installed.