I'm in the same boat as hero.

(SPOILER)
My reasoning behind believing Laguna knows of Squall being his son is Kiros' comment in the Ragnarok on Disk 4 (which I posted in the other thread related to this subject earlier today).

Meanwhile, Squall seems as clueless to his relation to Laguna as he does about everything else. There's nothing in his dialog that suggests he has a even a suspicion, and if he knew, he'd be asking a lot of questions.