Can I determine the service pack for all my SQL Servers using SCCM?
Very quick and easy solution would be to setup a CMS (Central Management Server)
This enables you to run queries on groups of servers.
So if you make a production group, you can run a query on all of them at the same time
Using
SELECT @@VERSION

Would return you all the versions of the group.
If you're managing a bunch of different servers, a CMS is always a very helpful tool.