Print To File is the functionality you're referring to, and it's relatively new in common applications. I noticed Microsoft has started to promote it with their Print to XPS and Print to Onenote features for MS office. Print to XPS has the annoyance of being a new file format, Print to Onenote is amazing but you have to know onenote to get it.
In 4 years of college I met a great deal of people that were very surprised that I could "print" papers on my computer and mark them up in Onenote (this was largely before the popularity of the iPad, mind you), I would say it's a fairly foreign concept to a less adept user.
"Print" means paper to most people, they would consider what you're doing something different, saving or downloading a document/file. Most people who browse the web are familiar with such functionality. I would word it in that manner, and if possible present it as an alternative to printing, rather than treating it as a printing option (even though it is). You can present a dialog to select your print location, and show something like this:
Print: [printer dropdown]
Or Save to PDF
That way you present the options at the same time but avoid confusion. Depending on your menu setup "Save/download as" could be an alternate to "Print...". Google docs is a good example, their "Download as" menu lets you pick a file format similar to a printer menu, but keeping the dead tree options in the "Print..." item.