While there are no major changes in the Software Inventory component between ConfigMgr 2007 and ConfigMgr 2012, Hardware Inventory has been enhanced.
ConfigMgr 2012 gives you the ability to create custom hardware inventory and extend the inventory schema by allowing you to add or import new inventory classes. This is without having to edit or modify the SMS_DEF.MOF file at all!
You can also define multiple custom hardware inventory settings so that each one can be applied across a different ConfigMgr 2012 Collection. This is a huge enhancement allowing you to fulfill requests properly, identify the proper hardware thresholds per office, department, or branch, et al, and minimize (in some cases) the amount of data retrieved.