After upgrading to System Center Configuration Manager 2012 SP1 CU1, you will be able to identify the update in many different ways.
First let us take a look at the console, after the update the console reports version 5.0.7804.1202
The console reported version 5.0.7804.1000 before updating.
The Console update is also listed in Control Panel as an Installed Update.
The site server will still report version 5.00.7804.1000 after the update.
In order to check if the update has been applied we must look in the registry.
CULevel reports 1 after CU1 has been applied.
Before updating CULevel reported 0.
This update is also visible under Installed Updates in Control Panel.
And finally the client will report 5.00.7804.1202 after the client has been updated.
Before updating the client reported 5.00.7804.1000