At Microsoft, We Listen To Our Customers! Eventually
Well, it took them a decade, it only works in Office 2007, and you have to download an optional add-on to do it, but you can finally have a "Save as PDF" option in Microsoft Office. No more need for hacks like a PDF printer driver.
Of course, the add-on also lets you save your file in XPS/"Metro" format. (XPS is Microsoft’s new PDF-killer.) Which should be useful for all of five or six people.
UPDATE (March 4, 2007): Raymond Chen points out in the comments that Microsoft would have had "Save as PDF" earlier had not Adobe threatened to sue them if they did it. Which probably explains why the "Save as PDF" feature is provided as an optional download for Office 2007, too, rather than an out-of-the-box feature. Raymond is one of the world’s better-known programmers, so I’m a little flattered that he bothered to take the time to correct me 🙂