Before I respond. let me post a SPOILER here that I'm going to mention something that takes place in AvX #12, for those that havent read it yet.

S

P

O

I

L

E

R

While its true that the Phoenix Force influenced Namor's actions, its also true that the influenced those of Cyclops, and yet now he's sitting in a prison cell for his crimes. Namor should not be held any less accountable. He deserves to be tried for what he did and let a jury decide if he's responsible, just like Cyclops presumably will.