User blog comment:Hunter89/Will be continued?/@comment-6697950-20131125171405/@comment-6697950-20131125190149

The manga is actually still ongoing.... well, we have 3 ongoing mangas to be specific. 1 based on Fairy Dance (still catching up to the anime, guessing a Phantom Bullet manga would begin after this one is finished), 1 Progressive (remember episode 2?, well, that was actually from a special reboot series called "Progressive" that basically shows how Aincrad was cleared one floor at a time... and the anime REALLY screwed up the adaptation of that story... the manga does MUCH better, though it does tell the story a bit differently) and we also have 1 spin-off manga called Girls Ops that has no ties to the main story and, basically, gives the Leafa, Lisbeth and Silica some spotlight that they lack in the latter arcs.

Anyway, there is no definite proof that the anime will get a continuation, nor is there any proof that it won't. As far as I understand, the reception of the story in the States is very good (even the books have become licensed in the USA due to it), though I'm not so sure about the anime's reception in Japan. The book is definitely popular, but I have heard rumours that the anime wasn't that well accepted. Of course, that's just something I heard and have no way of proving, so don't take it as legit information.

So, there are reasons to believe that the anime will get a continuation, but there is no evidence that it will, so it's pretty much a 50/50 thing right now. We'll just have to wait for this special episode to see if it's just plain fan service, or if the anime studio plans to use this episode for an announcement.

P.S. If you are interested in the story, I would recommend reading the books. The first book's English version will be officially released in April, but there are fan translations of the first 12 volumes and most of volume 13 that's in the proccess of being translated. Even reading the books covered by the anime is interesting, as quite a few details  were changed or just omitted in the anime (a few stories were drastically changed or had a lot of important details omitted...) or you could just read the story starting with volume 5, as the anime stopped with volume 4.