Best solution for exporting Word documents to PDF programatically (without using a "software printer")?

I'm looking for a way to export a Word document as a PDF. I would like to do this without the use of a "software printer" (such as CutePDF, 开发者_StackOverflow社区etc.) and stick to reference assemblies if at all possible. I'm using Microsoft Office Interop Assemblies to generate a Word Document which I save to a temporary directory. So its not necessary for this solution to interact directly with Microsoft Office, unless it needs to.

Office 2007 has a built-in (or add-on) converter to PDF, therefore you can save office 2007 files to PDF without much hassle.

Otherwise, you'll have to use some sort of conversion assembly (there should be commercial assebmlies that perfrom this task), or a converstion application that can receive command-line arguments, or maybe even some web-based service for office-to-pdf conversion.