Fans still hunger for the continuation of Sword Art Online. After Season 2, where could the story be headed?
As one of the highest rating anime series, profits for Aniplex and A-1 will prompt them to continue the series as stated in the Sword Art Online Reddit page.
"Yes, yes, yes. Although nothing has been confirmed, profits for SAO are through the roof. The producers would be stupid if they didn't make a Season 3."
It would also help that the anime is also rating well on Netflix. As the media streaming giant gains more influence, they may prompt a 2016 release although this has not been confirmed yet.
Season 2 ended with the Mother Rosario arc which was covered up to volume 7. Volume 8 was composed of side stories, foremost of which was Caliber, so Season 3 would take off from Volume 9, including the Alicization arc.
The movie release would not affect this as it has already been confirmed that it will feature an original story that would take place after the Mother Rosario arc. This was confirmed by author Kawahara Reki on Dengeki Bunko Magazine Vol.46 (h/t Dreadful Decoding for the translation:
"We have decided to endeavour an original plot for this one as well, thankfully. As for the content, the pivotal aspect of 'Sword Art Online' - that this is a story with Kirito and Asuna at its centre - will be the same as always. Of course, highlights for the other characters will be prepared as well, thus I believe that the fans of the respective characters will have something to look forward to. This story is going to take place before the latest novel in chronological order. Because even I am not sure what the situation of the series's world will be after the 'Alicization' arc."