I posted this theory elsewhere, but as it is relevant to this thread, I think it's reasonable to present it again.

Belkar will continue to be in the comic after his demise, but NOT as an undead, demonic plant-golem!

Sheesh, some of the theories that crop up about him are so silly!

He will remain in the story partly because he's such an entertaining little creep, and partly because he's going to be in the perfect position to provide us with a view of another unexplored region in the Order of the Stick Universe; Hell.

Belkar will go to Hell upon his death, never to draw another breath, but he will still play an important part in the story, just as Roy is still in the story, despite having been in Heaven for the last few million episodes.

I expect that V will go to Hell at some point, while paying off his/her soul-debt, and have an extra-dimensional side-adventure with the Late Belkar.