Hi Nikhil,
basically yes, there is little you have to do after upgrade. You may have to review the XCM based url settings, maybe reset passwords in J2EE Java Connector (Config UI uses this connection to read customizing and other data from CRM in real-time).
You may also encounter problems with IE and server security, because the UI is rendered by different server (J2EE) than rest of the screen (CRM ABAP stack).
In CRM 5.0,m if you have used SAPgui access, there was no problem, because the J2EE screens were embedded in SAPgui.
Check, for instance, OSS note 974260 - "Permission denied" on "Done" or "Back" in Configuration UI.
Just one note more - I would go for CRM Ehp4, which was recently released, or EhP3, if you want to be on a safe side.
Regards,
Dawood.