When integrating MDT 2012 Update 1 with ConfigMgr 2007/2012 the Computer Replace scenario is unfortunately badly broken. How the test team could miss testing one of the core three deployment scenarios I don't know, but I know how to fix the bug.
When using the Computer Replace scenario in ConfigMgr, unlike the Computer Refresh scenario, the state migration point is being used. To access content in the state migration store, the Request State Store action is used. In the standard client task sequence in MDT 2012 Update 1, that action is missing, leading to that the backup from the old computer is never restored.
In the smsts.log file you find the line: The action (Restore User State) has been skipped because the condition is evaluated to be false. Here is a sample smsts.log file.
The reason for the above is that the OSDStateStorePath property is never set (by the Request State Store action). When opening the task sequence you can clearly see that it's missing that action in the State Restore phase. The fix is to add a Request State Store action before Connect to State action, and set a condition so it's only used during a computer replace (and not during a computer refresh). You also need to add a Release State Store action after the restore has been completed, meaning after the Restore User State action.
Adding the Request State Store action before Connect to State action (also set the Restore state from another computer option, and select the If computer account fails to connect to state store, use the Network Access account):
Set a condition to the added Request State Store, to only be used during a computer replace, add a task sequence variable condition, the condition is USMTLOCAL not equals True (see below), also configure the action to Continue on error:
Then add a Release State Store action after the Restore User State action, and set the same condition. Also configure the action to Continue on error. Now you have a task sequence that looks like this:
You now have a working computer replace scenario in ConfigMgr 2012 integrated with MDT 2012 Update 1!
Here is a smsts.log file from a successful computer replace:
Happy deployment, Johan