Forget about writing Atom or RSS XML handling code ever again
A *very* welcome addition to .NET 3.5, which just went RTM for MSDN subscribers and trial for the rest before general availability early next year: System.ServiceModel.Syndication.
This namespace, which lives in the System.ServiceModel.Web.dll assembly which provides the WCF Syndication functionality, contains useful classes for working with feeds and items. I won't go over the Architecture of Syndication...