Well I believe that when you move to WLC code 7.2 you need to move up to NCS. Cisco does have a special upgrade for cheap til maybe close to the end of the year to upgrade WCS to NCS. Take a look at the 7.2 compatibility matrix. That will show what is supported on what version of WLC code.
Back in October I was on a monthly mobility sales conference call with Cisco and it was said during this call that the WCS is nearing end of life. Now how accurate this is I cannot vouch for as I had expected to see a more formal announcement at this point... Current EOL info for WCS http://www.cisco.com/en/US/products/ps6305/prod_eol_notices_list.html.
I'm not sure they'll be releasing software updates for the WCS though as they likely would have done it at this point... Although you never know.