1. FD: I didn't go through the whole flow.
2. I post at Post.ly (See #3 -- because I'm wondering under which context I would even post in Post.ly), and it creates a Posterous blog (wait, you're setting up a blog for me? you didn't mention that... what if I already have a blog?) -- and then links the Tweet to it. This seems even more like a bastard child to me now than I originally thought, not to mention a completely confusing user experience.
3. What exactly is the audience here. Most tweets are about referring to existing content (at least the tweets with links) -- under which context are you saying -- "here world, here's a random webpage I just created out of the blue with some files" -- wheres the story+context here?
I maintain my stance, this seems like a desperate attempt to jump on the Twitter bandwagon instead of really thinking about how to make your core product more valuable.