Forgive me of my limited networking knowledge, but I'm pretty sure as long as those servers can still be resolved by DNS and you can connect to them over port 4750 post-NAT firewall change, all you would want to do is run an Update Properties Job to ensure connectivity and you should be good to go.
greg, you are correct. however, there is a very important distinction which needs to go in there...
the dns records here are key and may result in two sets of records for the same set of servers depending on name resolution requirements. consider, for example, that the appserver is in subnet A while the targets are in subnet B. if you need the servers within subnet B to be able to resolve eachother by name, then you'll need DNS entries for that subnet. however, in order to execute jobs from the appserver (residing in subnet A), you have to have another set of DNS entries for the appserver to use.
this results in two sets of records for the same servers, depending on where the queries are being executed. those in subnet B will resolve to the actual IP, while requests from subnet A will result in the NAT'ed address.