Microsoft confirmed that they will be releasing Office 2010 in June of 2010.  It is codenamed Office 14.  This will be their first version to support 64-bit processors.  So you will not have the 4GB memory limit in your future Office suites if you go with the x64 version.  32-bit users not worry there will be two versions.  Another new feature of Office 2010 is a web based version.  It is said Microsoft will also offer a free web based version with ads.