Odd, I've been checking in w/jodi.org every couple of months, and especially after coming across the "windows racing around the desktop" one I've even giving it out to customers to test their browser for the ISP I used to work for. It does NOT crash any browser I've ever come across (haven't tested it on Opera, though), although it DOES crash a net-newbie's patience!
I have a feeling the above warning email is just another cutting-edge jodi.org stunt, and I hope this is the case :).
P.S. This site is listed as a reccomended site in the hardcover book, "Cutting Edge Web Design". Ahh, fame!