User blog comment:Yauza44/Zeref/@comment-1839664-20101101181853

...Nah, there's still too much loose ends left untied... the Dragons, Raven Tail, Tartaros, new Magic Council's dictatorship, other countries they have yet to visit on Earth Land, Lucy's mom, all twelve zodiac celestial spirits (and potentially a specific arc about it), Jellal's true plan, etc. The point is that it will still take a while (really long while if Mashima draws each of these arc, which I estimate at least 6 more years) to tie up all the loose ends.