I am doing a Nugget on T4 at the NxtGenUG meeting at Coventry on 12th July 2010. The main event talk is Dave Sussman on How Clean is your ASP.NET?
The Nugget is a brief introduction to T4: what it is, what you can do with it and how it can make boiler plate coding far less dull and error prone. There have been a few minor changes since the nugget I gave in April. The demo project is VS2010 and uses a EF4 model rather than WCF data services model.