After you have installed CU1 for ConfigMgr 2012 SP1, the client will update to version 5.00.7804.1202
You can create a query to grab the inventory for the client and identify those computers that have successfully upgraded to the new client (or not).
Use the following query to retrieve the list of computers that have the upgraded client:
select SMS_R_SYSTEM.ResourceID,SMS_R_SYSTEM.ResourceType,SMS_R_SYSTEM.Name,SMS_R_SYSTEM.SMSUniqueIdentifier,SMS_R_SYSTEM.ResourceDomainORWorkgroup,SMS_R_SYSTEM.Client from SMS_R_System inner join SMS_G_System_SMS_ADVANCED_CLIENT_STATE on SMS_G_System_SMS_ADVANCED_CLIENT_STATE.ResourceId = SMS_R_System.ResourceId where SMS_G_System_SMS_ADVANCED_CLIENT_STATE.Version = “5.00.7804.1202″
Download the query: CU1 Client Query