My point is not that they are the same, but that details matter a lot, and that just because there are parallels between two things, it does not make them the same thing. My .plan example was not made up -- that was an actual criticism from the early days of blogging (according to Jason Shellen, who was part of Blogger).

(Just read Jason's piece the other day, actually. You can't leave comments on a .plan ...)

I agree that details matter a great deal. In any event, the comment specifically questioned the temporal aspects of the analogy. Wishing you success in your endeavors.

IM and IRC are fundamentally different from twitter and friendfeed, because twitter and friendfeed have home pages with content. Deciding what goes on the home page is key functionality that wasn't in IM or IRC.

Some IM protocols allowed one to set up some info which is public and supposed to act as a bio. This content could be some form of HTML, which is more than anything twitter supports (i.e, it let you do the styling, much to the detriment of others).