Yes, fully supported.
The Data Sheet is the most up to date at the moment and does list Sup32 support:
http://www.cisco.com/en/US/products/hw/modules/ps2706/products_data_sheet09186a00801e55dd.html
From the Data Sheet:
For Cisco IOS Software Release 12.2(18)SFX4, the following features are supported on the Supervisor Engine 2, Supervisor Engine 32, and Supervisor Engine 720: inline VLAN pairing and Cisco EtherChannel load balancing
For Cisco Catalyst OS 8.5(1), the following features are supported on the Supervisor Engine 1, Supervisor Engine 2, Supervisor Engine 32, and Supervisor Engine 720: inline VLAN pairing and Cisco EtherChannel load balancing
NOTE:
The CLI User Guide was written before Sup32 support had been added and so it is out of date. The information in the Data Sheet is accurate.
