WARNING -- BIG SPOILERS!!!
Someone sent these script pages to me, looks like McGarrett's mother is going to have a big problem next season!
But maybe these pages should be taken with a large grain of salt?
There was some news today which I saw which involved a casting call in Los Angeles which required an actor which was going to a double for O'Loughlin, but this seems to have disappeared, maybe this has some connection to this plot development.
http://fiveohomepage.com/2010-season10/spoilers/