Why is Atom important?

I'm down at the O'Reilly Emerging Technology Conference this week learning some new things and provoking some new thoughts in other areas. I've got months of writing material.

I was talking to Doc Searls this afternoon about identity related stuff, trying to get a read on his thoughts when the conversation wound around to Atom. He asked me why I thought Atom was important. My reply, as I remember it:

Atom is to weblogs (and potentially to many other web applications) what pipes are to unix applications. It is both an output and an input mechanism which makes it very powerful in my mind and gives a whole new meaning to the concept of information flow.

That's my high level view (and one less thing on my to do list).