So far, Flickr rocks. It’s still officially in beta, and things change/improve almost daily. The site is a great combination of easy to use and geek-friendly. The developers are focused on all the right things. There seems to be a core set of ideals that touch on things like standards-compliance, ease of use, extensibility, accessibility and other goodies.
I’d never heard of FeedBurner. They basically take your feed and tweak it in all sorts of configurable ways. As an example, over on your right is a FeedBurner icon which links my “burned” feed. It automatically chooses the format (RSS/Atom, etc) based on the parser and can do all kinds of wonderful things I’ve yet to discover.
They are both pre-release products that will be well worth watching.