If it's ambiguous he isn't dead. That's one of the many reasons I started to stop caring towards the end of season 4. I have watched season 5 but it didn't stoke my interest, so I've just not bothered continuing.
All the characters are just too damn pathetic. That's what happens if you make a show HARDCORE, the characters just become moronic, power-hungry, nymphomaniac warmongers. All without any sense of dignity because any kind of intellectualism is deemed as "weak" and these "brave" men and women have so little self-integrity that they can't handle slight disapproval.
That was a long rant, but if you still think that bloodthirsty barbarians are strong and unyielding, you need to remember where all that blood comes from.
What do you think?