Well personally I think this is not really the end, I firmly believe that some things about this marvelous history will not remain untold.
Also, it appears that miracles do exist......maybe.
Because its possible that there is going to be another manga of tokyo ghoul that serves as a continuation to the former. I learned about this in certain website very-known where it says the following:
This year's 45th issue of Shueisha's Young Jump magazine is revealing on Thursday that Tokyo Ghoul manga creator Sui Ishida will launch a "shocking new series" in the following issue on October 16. The new manga will have a 45-page first chapter with a color opening page and art on the magazine's cover. The magazine teases, "The legend has a beginning. If you bear witness to this beginning, it will be a moment you will never forget as long as you live!!"
I think that a lot of you must this website, yes, I am talking about Anime News Network here it is the link to entire article, I recommend you to check it out: http://www.animenewsnetwork.com/news/2014-10-04/tokyo-ghoul-sui-ishida-to-launch-new-manga-in-october/.79550.
I hope that "new series" be related to Tokyo Ghoul, but this is, as the tittle says, a maybe........
I will to read your opinions about this matter, I mean, as a fellow fan of Tokyo Ghoul.
P.D: I am not criticizing the ending of the manga, I just expect that there is more...... maybe I am just naive.