I've been using Zimbra Desktop 1.0 for many months and always used the export account feature to make a backup of my data in case of a major failure or my hosted Zimbra provider. This always worked fine, no idea if I can restore (never tried) but at least I could salvage my emails from XML files if I wanted to.
I tried doing the same once I finished installing Zimbra Desktop 2.0 (I even rebooted just to make sure everything was properly installed) but the export function does not create my 750MB backup file, only a 6.6k file containing only .meta files.
I didn't find any mention of this on the forum so I'm reporting it in case the problem was not previously reported.
Except from that, the switch to 2.0 went flawlessly, only my tags were giving me errors the first time I accessed them from the tree, but they were OK once I went to my account in web mode and back to Zimbra Desktop 2.0.