The blog is incredibly open. seeing it all go up with the notes around the creative process is quite fascinating even if you cant follow all the math [and I guess only 50 people in the world can].

Having the math inline works really well [wordpress renders latex formulas as pics with the latex as alt text] - you don't have to jump into a pdf viewer while parsing the main text. Its one way to get started with latex, ie. by example.

Terry and Timothy Gowers are experimenting with an approach to creating math with lots of small involvements by many contributors online - see http://gowers.wordpress.com/2009/03/24/can-polymath-be-scale...