On another occasion, we noted Dean Zimmerman's powerful critique of middle knowledge. Here's another: Keith DeRose's new paper, "The Conditionals of Deliberation", Mind 119 (Jan. 2010). Here is the link. For a more explicit connection between the paper and the problems it poses for middle knowledge, see this related ancestor to the paper. This of course raises problems for Plantinga's specific version of the free will defense (although not necessarily for other versions).