DeeCee - 11:37 pm on Feb 26, 2012 (gmt 0)
The pattern looks exactly like the usual Twitter swarm.
You or someone else puts a message on Twitter with a link leading to a page, and all the dumb bots subscribed to the global Twitter stream starts attacking. Some to get the post, some just to resolve the shortened URL and take metadata (such as JS-Kit URL Resolver and MetaURI), and others are typical "sharing services" (such as FlipBoard and PaperLi) making a living of our posts.
I have Wordpress connected to Twitter, and these same patterns start every time within 1-2 seconds after a Publish. And continues slower for hours after the Twitter post.
I have many of them blocked. Especially if they do not have a real name (such as JS-Kit, which is merely a library and could be anyone), or all the ones running hidden inside Amazon EC2, where you really have no idea who they are, no matter what name they pretend to have.