Rick:
MSDN: Building a Desktop News Aggregator via Jeff Key’s .net blog.
It’s a cool article and nice C# demo app. It looks like it assumes that any given feed that it tries to chomp is valid and well formed and all (of course we all know of an RSS parser that can handle anything you throw at it), but it does handle 0.91, 1.0, and 2.0.
I’d like to see Dare Obasanjo go into a little more detail, show and explain a little more code, but the article is well worth reading.