I wanted to know similar things and went and tracked down copies of the 2010, 2011 and 2012 catalogs to compare. Couldn't tell you exactly how I located them, but try a google search. I don't believe there were too many visible changes between the 2011 and 2012. Somewhere in there a guide pin was added to the drive unit, but I forget if that was new in '11 or '12.
As far as what is coming in 2013, Hobie won't say a word about it until sometime in August when the new models are formally announced.