Apple announced their update to .mac as and

Apple - MobileMe - A Guided Tour

It sounds and looks an awful lot like a skinned version of Zimbra to me. As described in the video, it is a drop in replacement for exchange and they can sync to iCal, iPhone via active sync and PC's with outlook 2003/2007. Again just like Zimbra. Coincidence, sure, but why has Apple not released this as a server product? It's unlikely that they would develop this all from scratch.
The final piece that did it for me was the fact that the iPhone software 2.0 Beta application listed exchange and Zimbra as the only email server options.

This would probably mean not too much, other than hopefully some cross development opportunities to make Zimbra better. It's also no too hard to believe they could do this given that Yahoo and Comcast deployed this as their hosted email solution.

If so Cool!! If not who did they use?