I have virtual center that manages a few ESX hosts and I would like to join it to my Active Directory domain. What things should I consider when making this move? Is there any reason why I would want to avoid this? I believe it will make user management in virtual-center easier.
I agree with voretaq7 - there is no reason NOT to put vCenter on a AD-joined server when you have the option.
A word of advice though - vCenter behaves bad if you mess around with service accounts etc. I'd strongly consider reinstalling vCenter (and all it's children) if you're planning to join the server to AD and already have vCenter installed.
I see no reason not to do this - In fact from my totally-not-a-windows-admin-and-VirtualCenter-runs-on-a-standalone-box chair it seems to be the Right Thing to do in a Domain environment.
Just be sure you set appropriate VirtualCenter rights for your users and you should be fine...