From TV By the Numbers:
Tonight is the season finale for Heroes. Will it also be its series finale?
The ratings have been so poor this season that even on lowly NBC its numbers would lean towards cancellation. But NBC is in such turmoil it will likely at least consider renewing the show anyway.
I know people will talk about DVD sales, international licensing, etc. and while they might aid its status, on a healthier NBC, I don't think those factors would come into play.
However, things are in such turmoil at NBC that I can easily imagine a world where NBC would bring it back for another season anyway either as a relaunch of what NBC perceives as a popular and solid brand, or for one final season as a send off.
Heroes renewed? Heroes canceled?