Recently I experienced an issue with SCVMM 2012 where I needed to remove a vCenter which exists at a remote site.
Trying to remove the server from the console caused VMM to try and perform an inventory update before removing the server which resulted in this error, due to the inventory job taking quite some time to complete:
Error : Unable to perform the job because one or more of the selected objects are locked by another job.
To find out which job is locking the object, in the Jobs view, group by Status, and find the running or canceling job for the object. When the job is complete, try again.
After trying several methods with no success, including powershell, I tried a last ditch attempt before resigning myself to Microsofts solution http://blogs.technet.com/b/scvmm/archive/2012/07/16/kb-attempting-to-remove-vmware-vcenter-from-system-center-2012-virtual-machine-manager-fails-with-error-0x8007274d.aspx which is rather extreme.
I ended up requesting the VMware admin remove the access for my SCVMM run as account, which caused the inventory to fail immediatly and not lock the objects. This enabled me to remove the vCenter without resorting to drastic measures.
I did later come across another solution which is unsupported http://digitaljive.wordpress.com/2012/07/06/scvmm-2012-force-remove-vcenter-server/
Hopefully Microsoft will provide a better solution for this issue in the future.