Steven Sinofsky of the Office 12 development team unveiled last week that version 12 of Office will include native support for the PDF format.
I constantly get asked by customers if we can build in this support for publishing documents as PDF files, and now I can thankfully say "yes!" It's something we've been hearing about for years, and earlier in this project we decided that while there were already existing third party tools for doing this, we should do the work to build the functionality natively into the product.
The PDF support will be built into Word, Excel, PowerPoint, Access, Publisher, OneNote, Visio, and InfoPath! I love how well this new functionality will work in combination with the new Open XML formats in Word, Excel, and PowerPoint. We've really heard the feedback that sharing documents across multiple platforms and long term archiving are really important. People now have a couple options here, with the existing support for HTML and RTF, and now the new support for Open XML formats and PDF!
More info about PDF support in Office 12 can be found over here.