I've presented at two of the TechNet Updates now travelling the country. There's a couple of things in the decks that people have been really interested in:
1. Peer caching capability - Picture a scenario of two PC's on the same subnet that contact the same WSUS 3 server. The first one realises that it needs the update, downloads it and applies it. The second PC also discovers an hour later that it also requires the same update. It goes to download the update from WSUS 3 that it requires and rather than it getting the update directly off the WSUS server, the client nearby on the local subnet that downloaded it earlier responds from its BITS cache that it already has the update and that it can download it from it instead. This has the effect of reducing WAN traffic and in Microsoft's internal network we have found we had a 70% BITS peer cache hit rate. You enable it through the BITS peer caching function and is not switched on by default.
More information here: Appendix E- Configuring BITS 2.0 and 3.0 for Download Performance
2. WAN flooding - imagine a big service pack comes out. Actually that's not really that hard to imagine....:) The client goes to download it from the WSUS server along with several others. The network floods for other traffic that also shares the same pipe. You can throttle BITS performance down so that it essentially drizzles better rather than floods. See the above link for configuration information but also see the below one for IIS config.
More information here:
IIS configuration - Appendix F- Configuring IIS for Download Performance
3. Client Configuration Issues - this seems to be a common issue ranging from self update failing to the annoying "not yet reported" problems. I provided some guidance to resolving some of these though there's some basic information at the link WSUS 3.0 Client Computer Administration Issues.
4. Best Practises - lots of stuff in here I presented on http://technet2.microsoft.com/windowsserver/en/library/44f3c301-0f79-425a-a2e5-a9854360ae9b1033.mspx
Shortly, after the Melbourne TechNet Updates are completed Ill post the deck with lots of other client troubleshooting information in it.
Theres some great guidance on the TechNet site about all the WSUS 3.0 improvements and configuration guidance. Check it out at Windows Server Update Services 3.0