Adobe has stated this will be available with the next major release of Acrobat and they have no intention of updating version 6, 7, 8, or 9 for MS Office 2010.
There are some otter products out there that are now compatible with MS Office 2010, but they are not as robust as Acrobat. You can use OpenOffice.org's office suite to read MS Office 2010 Docx files and convert them to PDF. Nitro PDF and Nuance both have programs that can convert MS Office documents to PDFs.
Office 2010 does have 'Save as PDF' file option.
George Kaiser