FWSM supported with 15.1(1)SY on VS-S720-10G in VSS mode

Cisco does not seem to keep public changelogs of its release notes. The ones of IOS 15.1(1)SY for Catalyst 6500 just got updated to state that the FWSM is indeed supported with this software version on VS-S720-10G (Sup720-10GE) in VSS mode. The previous revision said that only non-VSS mode is supported.

More IPv6 features on Cat6500 and ASA

Cisco published the unified Sup720/Sup2T 15.1SY release which brings features like OSPFv3 IPsec authentication, OSPFv3 VRF-lite, EIGRP IPv6 VRF-lite, RA guard and RADIUS/TACACS+/TFTP over IPv6 to Sup720 and IPv6 PBR in hardware to Sup2T.

For the ASA release 9.0 was made available, which (finally) includes features like DHCPv6 Relay, OSPFv3, Unified ACLs, IPv6 ranges, IPv6 for VPN, NAT64 and IPv6 NAT.

For more see the linked release notes. Also be careful what chassis types are supported by 15.1SY on the Catalyst 6500 if you have a support contract. I can confirm that it does boot on VS-S720-10G in a WS-C6509-NEB-A chassis even though it is not listed, but it is possible that Cisco refuses support for this combination.