Before i begin i would like to make it very clear that this post is riddled with spoilers

Based on the picture above i predict that…
…in the process of claiming Ciel’s soul, Sebastian must transfer his conscious into Ciel’s body, therefore living as Sebastian Michaelis in the body of Ciel Phantomhive. After this happens i believe the story can move in two different directions. Ciel[Sebastian] will either go back to London or another part of the world. If Ciel[Sebastian] moves to another part of the world he will serve a new master and the story will be about that. If Ciel[Sebastian] goes to London he will serve under the royal family and the story will be about the rebuilding of London and so forth as well as the corrupt undertones of the church of England. The main reason i came to this conclusion was due to the infamous quote “im one hell of a butler…” . As well as how Sebastian repeatedly told Ciel that he would be there to the very end, until he heard checkmate(PLUS…a dead Sebby is just oh-so-sad). Sebastian also raised Ciel, keeping him fit and healthy, possibly in preparation of taking his body for his own? I also predict that this season will delve more into the past of Sebastian, as well as flashbacks of the previous Master’s he had served….
Now this is merely speculation, my imagination was running wild so i decided to post it. As i have said before this is merely speculation, just a fan giving his 2 cents…
(translation of the poster)
Title: The Shape of the Future
Below the Title:
A shocking finale. But, what if, [the story] headed towards this conclusion…. Before the sequel [airs], what kind of future do you predict?
Sebastian’s “Last Scene” Box:
Sebastian Michaelis
As a perfect butler, he is absolutely obedient to Ciel’s orders. His goal, as demon, is to obtain Ciel’s soul. Having won the battle with the angel Ash, will that desire be fulfilled?
After urging [Ciel] to absolutely not not open his eyes until the count of 10, Sebastian returned to his repulsive true form. Ash’s repeated cries of “unclean!” were quite shocking.
At the very end, Sebastian continued to be a one hell of a butler. As the time of Ciel’s death drew near that was something that remained unchanged.
Through his fading consciousness, the last thing Ciel lays eyes on, is the black-tea colored eyes of Sebastian who is approaching while smiling suspiciously…
Ciel’s “Last Scene” Box:
Ciel Phantomhive
A loyal servant of the Queen of Great Britain. The young head of the Phantomhive house called the Queen’s Watchdog, and the master of a contract with the demon Sebastian. In front of the eternally resting Sebastian, what will he feel, what will he grieve?
As he promised Sebastian, Ciel absolutely didn’t open his eyes. As he drown in the depths of the deep River Thames, what [images] were floating beneath his eyelids?
As if traveling towards death, nostalgic days were reflected on the water’s surface. Surrounding Ciel at one time, were servant who wouldn’t be quiet even if you asked, and also a warm family.
Sebastian softly runs his hands over the eyepatch of Ciel, who’s accepted [what's about to happen]. Since the way he touches him seems somehow meaningful, there were probably alot of very excited people.
Large Text on the Right:
Sayonara…Sebastian…
In the Circle:
Tell us about it
Second-Season Butler
The Blurb Below That:
Thanks to everyone, a second season has been greenlit! For all of your warm support, thank you very much. What it’s contents will be, that’s still a secret but, we’re working hard not to betray your expectations, so please look forward to it! (Producer Iwata Mikihiro)