I didn't see anything about this that made me think it was limited to just the NE, and I can't find anything that says it's specifically for 7.x. I was trying this on my home FOSS server before trying it at work on our NE server, and my installation is hosed. I don't even have the web interface or the admin console to log into any more.
Network Edition: Moving from 32-bit to 64-bit Server - Zimbra :: Wiki
Does anyone have a pointer to instructions for migrating from 32- to 64-bits on Ubuntu 10.04, using FOSS edition? Because, at this point, it looks like my recommendation will be to NEVER move to it at work.