When migrating to SCCM 2012 there can be a good way to keep track of the actual agent status over time using dynamic collections. This since the agent upgrade has an automatic roll-back if the upgrade failes.

These collections can be used for both workstations or servers by using Limit to Collection in the query for the following:
All Windows Workstation or Professional Systems
All Windows Server Systems

(The settings for date and time must be based on how the current setting is made oh HW inv client agent)

List Active Computers:

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_COMPUTER_SYSTEM on SMS_G_System_COMPUTER_SYSTEM.ResourceID = SMS_R_System.ResourceId inner join SMS_G_System_OPERATING_SYSTEM on SMS_G_System_OPERATING_SYSTEM.ResourceId = SMS_R_System.ResourceId where SMS_G_System_OPERATING_SYSTEM.Name like “Microsoft%” and SMS_G_System_COMPUTER_SYSTEM.Name not in (select SMS_R_System.Name from SMS_R_System inner join SMS_G_System_WORKSTATION_STATUS on SMS_G_System_WORKSTATION_STATUS.ResourceID = SMS_R_System.ResourceId where SMS_G_System_WORKSTATION_STATUS.LastHardwareScan <= DateAdd(dd,-1,GetDate()))

List Non-Active Computers:

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_COMPUTER_SYSTEM on SMS_G_System_COMPUTER_SYSTEM.ResourceID = SMS_R_System.ResourceId inner join SMS_G_System_OPERATING_SYSTEM on SMS_G_System_OPERATING_SYSTEM.ResourceId = SMS_R_System.ResourceId where SMS_G_System_OPERATING_SYSTEM.Name like “Microsoft%” and SMS_G_System_COMPUTER_SYSTEM.Name not in (select SMS_R_System.Name from SMS_R_System inner join SMS_G_System_WORKSTATION_STATUS on SMS_G_System_WORKSTATION_STATUS.ResourceID = SMS_R_System.ResourceId where SMS_G_System_WORKSTATION_STATUS.LastHardwareScan >= DateAdd(dd,-10,GetDate()))