I think he will come back somehow.or at least hope

Knowing it's the CW, I'm betting he comes back as a ghost. That way he'll be able to look in on the boys.

This episode killed me. It was such a love letter to all Bobby fans. While the possibility of loosing Bobby upsets me, I think the episode was really well done. I was happy to see Bobby express how much he loves the boys and thinks of them as his own. I'm worried that if Bobby is dead, especially so soon after whatever happened to Cas, Dean is gonna be a total basket case.

From what I've read on iO9, he'll be back for at least one episode this season. I'm guessing he's coming back as a ghost.