While this effort is currently underway, the MacBU states they won’t be able to complete it because they decided to focus on other matters first. Microsoft needs to complete the transition from Carbon to Cocoa before it can build 64bit versions of Office, since Apple decided not to transition Carbon to 64bit. While it won’t affect users in any meaningful way (unless you use gigantic spreadsheets or something), it has some Mac users riled up. Microsoft has not yet completed the transition to from Carbon to Cocoa since it has focussed on increasing compatibility between Office for Windows and Office for Mac, and since Carbon is only available in 32bit, Redmond doesn’t really have a choice.
While WWDC is underway, Microsoft’s Macintosh Business Unit has announced that Microsoft Office for Mac 2011 will be available in 32bit only.
