PDF Preview (Outlook and Explorer) should work in Windows 7 with Adobe Reader installed (this contains preview handler). However due to the broken (for 2 years) Adobe installer not inserting correct registry key it does now work in 64 bit version. There is a very simple tweak (download .reg file and click it) to make it work.
Full details are at http://www.pretentiousname.com/adobe_pdf_x64_fix/index.html
