Differences between 1.1 and 2.0

1. Generics are introduces in 2.0
2. Master Pages introduced in 2.0
3. Nullable datatypes introduced in 2.0
4. Profile Object introduced in 2.0
5. 2.0 Has built in Web Server
6. This article outlines changes to the code model, compilation, page lifecycle, and more - http://msdn2.microsoft.com/en-us/library/ms379581(VS.80).aspx