(Next step: Defining the general Atom protocol standard, which willenable interoperable use of Atom for things like blog editors.)
Cool new beta feature in AOL Explorer (http://beta.aol.com/projects/aolexplorer/index.html?): The Journals side panel. I'm posting this from AOL Explorer right now. Very nice.
This version lets you drag and drop selected text from the page you're viewing in the main browser tab. Really handy for commenting on things!