There virtually no implications specific to Exchange as far as changing IP address is concerned.This is of course assuming that the MX record at your ISP does not point to the IP address you are changing. You also need cater for how the clients on your network connect to the Exch server ie, do they use a WINS server to find it. The bottom line is that you can always revert to the old IP if you feel things are going wrong. Give it a try.
All the best,
surrounding yourself with dwarfs does not make you a giant.