It's Drew Conway. The guy is good, and he makes complex things very accessible. Sometimes, you need to understand the matrices behind the process, and that's great, lots and lots of books out there about the math. But sometimes you need to group up some data and you need a quick way to get it done mostly well. There aren't as many books out there to do this as there should be, and I look forward to this one.
I like (& use) R, but to say it is "for hackers" seems strange to me -- not really a "hacker" language. Seems like a bit of a marketing strategy(/gimmick) to toss that word into the title. Looks like a promising book, though i'd much prefer it be in a scripting language like Python.
This looks like it's using R to teach, primarily. I'm partial to "Collective Intelligence" (Toby Segaran's book)-- it's written with all python examples and appears to have much of the same content and approach (practical application > theoretical underpinnings).
Site is bouncing up & down for me, here's the scrib'd document he links to:<p><a href="http://www.scribd.com/doc/80949907/TOC-ML4Hackers" rel="nofollow">http://www.scribd.com/doc/80949907/TOC-ML4Hackers</a><p>Exciting!