If you are in the process of deciding whether to deploy Office 2010 32-bit or 64-bit, I recommend to read through the following content. Note that Microsoft recommends installing Office 32 Bit even on Windows 7 64 bit.
TechNet - 64-bit editions of Office 2010 Understanding 64-Bit Office Compatibility Between the 32-bit and 64-bit Versions of Office 2010 64-bit Client Installation of Microsoft Office 2010 Office Resource Kit Blog - Office 2010 64-bit editions 4SysOps - Office 2010 – 64-bit vs. 32-bit – Part 1: Installation Microsoft Office 2010 Technology Guarantee: FAQ