Out of curiosity, what exactly goes into moving a server?
Come up with a set of specifications
Estimate how many servers are required. In certain cases the "cloud" is easier to deal with since its more flexible and easier to scale with.
Find a provider
Find the right server(s)
Do the administration of user accounts, passwords etc. Making sure that security is stepped up and improved.
Appraise the software installed on it, check versions and compare them to the versions of software AM's currently running on.
Upgrade/install/remove software as appropriate from the above.
Start migrating services (IRC etc) over to the new server and test them there.
Migrate a test portion of AM over and start to get it running stable through intensive debugging.
Move over the databases and more testing
Test a bit more
and a bit more testing.
And hopefully done.
The other thing that I haven't included in the above is the experience/knowledge required to work in different operating systems and versions of it (Linux). I've only become familiar with Linux recently so it takes me a while to overcome some technical problems, thus delays.