Is Heroes Doomed?

After the news of Ugly Betty's cancellation, it seems nothing is safe from being cancelled. Especially Heroes!
Heroes has been seeing a massive drop in numbers of viewers over their latest series. They are currently in their fourth season and are hanging on by the grip of their teeth. NBC are currently making a decision on whether to keep Heroes or not, so the question I'm asking "Is Heroes Doomed?"

What do you think? Should Heroes be cancelled?