At the Cisco 4500 Chassis model comparison page it says the Supervisor 7E is "Hardware Ready" for SDN. It was released in late 2011. URL for that page can be found here: http://www.cisco.com/en/US/products/hw/switches/ps4324/prod_models_comparison.html
All info I could find on the Cisco 4500-X doesn't mention anything about being hardware ready for Cisco ONE/SDN. It was however released after Supervisor 7E and from what I've read it's based largely on the Supervisor 7E.
Has anyone found information confirming whether the Cisco 4500-X is hardware ready for SDN and will have Cisco ONE support in the future? It would be nice if there was a page that clearly summarized which switch models are "Hardware Ready" and will support OnePK over the next few years.