Interesting Outlook Office Communicator issue. After installing Office Communicator some users reported losing the presence indication in Outlook
In Outlook's Tools, Options, Other tab is an Enable the Person Names Smart Tag feature. Below it is Display Presence Status in the From field. The latter is greyed out. When a user clears the first option and applies the dialog settings they lose the presence indicator smart tag in Outlook. We found that if you checked the first option again the smart tag would pop up when hovering over a name in Outlook, but it wouldn't display persistently.
After googling in vain for a day I finally realized that this must be a registry setting somewhere. So I stumbled around until I found it. Since there appears to be no information about the solution to this problem (though several other's have posted in Usenet wondering what the solution was), I figured I'd post what I found here. Maybe someone will find it useful.
The registry setting that controls this behavior (HKCU\Software\Microsoft\Office\11.0\Outlook\IM\EnablePresence=1). I still don't know why this option is greyed out in Outlook (tools, options, other, display presence in from field) for me. But at least now I have a workaround. Hoping this helps others.