> what are the latest/greatest features in .net 2005?
As the version of the framework is 2.0 and not 2005, I assume that you
mean Visual Studio 2005 also.
IMHO:
:: That the html design mode finally WORKS without messing up the code.
:: That it can cope with, and uses by default, XHTML.
:: Refactoring
:: Masterpages
:: Generics (as Karl also mentioned)
:: Recompiling while debugging
:: Web pages are compiled when you save them and runs without rebuilding