I have already done the following. I have VS Express 2010 (trial) installed on my windows 7 machine.
Installed WIF 6.1 and WIF sdk 4.0 from http://www.microsoft.com/download/en/details.aspx?displaylang=en&id=4451
Installed VS C++ express to get Visual Studio command prompt
Tried to execute C:\Program Files (x86)\Microsoft Visual Studio 10.0\Common7\IDE\devenv /ResetAddin Microsoft.IdentityModel.Tools.VS.VSAddin.FederationAddin. This does not work as devenv does not exist on my setup
Added "Microsoft.IdentityModel.Tools.VS.VSAddin.Addin" to my user profile as described @ http://www.fascinatedwithsoftware.com/blog/post/2011/06/14/Add-STS-Reference-is-Missing-in-Visual-Studio-2010.aspx
Still on right click of webrole "Add STS reference does not display"
Question: Does this option appear for VS 2010 Express (trial edition)?