My client would like to upgrade from our current development 32-bit server to a much larger server running on a 64 bit platform.
I'd very much so like to just import a snapshot of my current server's AMI (the 32 bit), but I'm thinking I can't do that when moving to a 64 bit instance can I?
If I can, what about my libs? Do I need to reinstall a lot of my already installed and configured services?
Which distro? Some systems will have a mechanism to upgrade the entire system including all packages to ones compiled for 64bit, but usually that is messier than would be desired.
This might be a good chance to consolidate your clients software to an easy to use package that can be dropped into any running system. Launch a new clean 64 bit instance and work on collecting all the bits that are unique to your client, perhaps even writing a script to "setup" the system for him. This exercise would also make migrating to other platforms, expanding the architecture, setting up test systems, etc easier to administer.