The point is, if you want to 0wn my readers, just compromise Blogger, Technorati, Sitemeter, Zoomr or Feedburner. Or maybe something they depend on. Then you can hand out all of the browser exploits in my name you want.
It's not like attacking one site to compromise another has never been done, or that I haven't been targeted before. I'm just saying.
Web 2.0 is looking a lot like a huge interconnected chain of transitive trust. See also: myspace.