Hi Paul,
There is a 30 Demo license for the WCS.
This good doc should get you started;
This Cisco Wireless Control System (WCS) licensing and ordering guide presents ordering guidelines for new Cisco WCS SKUs and licensing information for existing Cisco WCS deployments that are being upgraded to support Cisco Unified Wireless Network Software Release 4.1. This guide includes information on buying new or expansion Cisco WCS licenses, migrating from CiscoWorks Wireless LAN Solution Engine (WLSE) to Cisco WCS, upgrading to the Cisco WCS Location option, and deploying the free Cisco WCS Demonstration License.
From this good doc;
http://www.cisco.com/en/US/products/ps6305/products_data_sheet0900aecd804b4646.html
Hope this helps!
Rob