1
From Microsoft:
Service Pack 1 introduces support for some new hardware and software standards, notably the exFAT file system, 802.11n wireless networking, IPv6 over VPN connections, and the Secure Socket Tunneling Protocol. Booting a system using Extensible Firmware Interface on x64 systems is also being introduced; this feature had originally been slated for the initial release of Vista but was delayed due to a lack of compatible hardware at the time.