You can duplicate the live server with rsync without many problems. You just can't rsync the entire system though. You will still need to configure DNS and Apache, but you can use the configuration files from the live system as a starting point. Your MySQL database won't copy over very well either. As far as web pages or apps, you can do something like the following from your new server after networking is configured:
Code:
rsync -ave ssh old.server.com:/path/to/webpages /path/to
HTH
Forrest