Dare: suffice it to say that I agree a lot with what what was said on "Spiral Dive". However, I'm less adamant about the one item at a time issue.
I tend to think of it a lot like I think of email. Yes, most mail programs mark items as read and unread and present them to you one item at a time, but it is also comparitively easy to find an e-mail that you received yesterday independent of such markings.
My guess is that where I will ultimately end up is with
HEP. The idea of unified email and blogging is attractive to me.
That would also explain the popularity of NewsGator.