We have an Office Communicator 2007 setup in my office. I’ve found this communication tool beneficial for our office environment. Two of the biggest benefits from this application is that people’s current status is sync’d with their Outlook Calendar. So if you have a meeting at 1PM, your status icon will immediately change to Red and mark them as "busy". This status indicator shows up in several places, including the IM contact list, anywhere in Outlook that their address is defined (address book, emails, tasks, etc.), and Sharepoint.
The second huge benefit that I’ve found in Communicator is that all conversations are saved and organized in a folder within my Outlook Mailbox. There are many more benefits that come with this program but these are my two favorite.
We recently ran into an issue with one someone’s computer not performing any of these tasks. Communicator worked just fine but these two "auto" features were not working and no errors were being reported. After quite a bit of troubleshooting and searching, I finally found an explanation on Microsoft’s website. This particular user had Office 2010 64-bit installed for the additional benefits in Excel. As it turns out, Office x64 is not at all compatible with Office Communicator due to this and there is no work-around.
Communicator integration If you install the 64-bit version of Office, certain Microsoft Office Communicator 2007 features that involve integration with Outlook are lost. For example, you cannot right-click a Communicator contact to schedule a meeting, send an e-mail message, or find previous conversations. This is because Office Communicator R2 is 32-bit, and Messaging Application Programming Interface (MAPI) calls do not cross the 32-/64-bit boundary.
More Info can be found here: office.microsoft.com/en-us/word-help/choose-the-32-bit-or-64-bit-version-of-microsoft-office-HA010369476.aspx
No word yet on if their newly re-branded product, Microsoft Lync fixes these issues or not.
Hopefully this can save someone else a few hours of frustration getting these two to play nice.