They talk for a bit and all, and then he says, "I'm sorry, but I want to sleep for a little while longer."
Besides the screen turning white as he fades back into his sleep while Ciel blabbers about wanting to know what took place with Arcuied, does this mean he dies later on?
Like, if he was supposed to die when waking up, did he only get to see Ciel for a certain amount of time before going to sleep forever? Would Ciel return home and find that Shiki was no longer breathing? Or did he overcome death and get to carry on with his life?
I think it points to the latter, but otherwise, Shiki dying soon after the end seems like a heavy possibility unless I'm missing something.