Just an idea:
VMware has just recently released a free player for vmware-virtual machines for Windows and Linux. It would be pretty cool if someone set up a base-vmware image with a linux-distro of choice and a ready-to-go zimbra installation for production-use. The player is free, even for commercial use. VMware even makes a few images available for download, for example a completely set-up Oracle Server The advantage of such a vmware-image is, that it could be used as-is in a productive environment. I think zimbra looks pretty cool and such a virtual machine would dramatically lower the barriers for testing and deploying it.
Just my 2 cents,