This of course has two meanings for an American -- which manga will finish serializing in Japan? And, which of these finished works will be fully translated into English by the end of the year?
I suspect a lot of manga will end in 2017. This includes Fairy Tail, UQ Holder, Hayate no Gotoku, Zettai Karen Children, Akame ga Kill!, Akame ga Kill! Zero, To Love-ru Darkness, Btooom!, Kyoukai no Rinne, and Sore ga Seiyuu!
Of these, I expect Fairy Tail, UQ Holder, Hayate no Gotoku, Zettai Karen Children, Akame ga Kill!, and To Love-ru Darkness will also be finished in translation.
I'm also hoping that series that ended years ago will finally be finished translating in 2017: Shinryaku! Ika Musume, Nichijou, Kiwaguro no Brynhildr, and Working Re:Order. I don't have much hope for other finished series that still aren't translated, they seem to be wholly abandoned by the fansub community, but I'd certainly welcome the likes of Kitakubu or Sakura Zensen receiving a translation this year as well.
In 2016, in terms of completed manga, all we got was Bleach (which was cancelled, not finished), Assassination Classroom (which was animated, so reading the manga is pointless), and Boku Dake ga Inai Machi (the main story was animated, so no point reading, and the Gaiden wasn't very good, so ho-hum.)
So if we go from these three not so stellar results to a projected 10 total finished, translated manga in 2017, as far as manga is concerned, we'll be thrice as well off as we were last year. 2017 might be a leaner year in terms of anime, but all of these spectacular finales in manga will make up for it. A lot of series that have been running so long they've felt like a permanent fixture of our lives are wrapping up this year. 2017 is a retro year for manga, but 2018 won't be.