I hear that VMware has announced their plan to acquire Zimbra:

VMWare announced on Tuesday that they are acquiring Zimbra from Yahoo! Inc. The maker of the popular VMWare Fusion virtualization software for Mac OS X, VMWare has been moving in the direction of providing cloud solutions, and the acquisition of Zimbra fits those plans perfectly.

Interesting. The two aren't a perfect match, but if VMware is looking at doing cloud services of some sort, it is (IMVHO) a good match.