I happened to me a few hours ago playing Resident Evil 5: the game frozen and now my PS3 can´t read any Blu-Ray (but still reads normal CD's and DVD's).

Everybody already said it, but call Sony. If your waranty hasn't expired, they should change it for a new one (make a backup of your saved files).

Forgive my engrish, it isn't my "mother languaje"