Apparently, they're planning to develop a full-fledged trilogy.

Rating: 9/10 (19 February 2017)

I don't know if they'll succeed, though. I mean, I went to see this on a Saturday afternoon during Opening Weekend...and there were only about a dozen people there (myself, included)!
Disconcerting? Yes. A guarantor of box office failure? Not necessarily.
I, for one, liked the way it expanded on John Wick's backstory. In the first movie, Nico Tarasov describes to his know-nothing son how John was given a seemingly impossible task to perform in exchange for being allowed to retire and marry his beloved Helen. We now learn, in this sequel, that John successfully accomplished it only because of unspecified help provided by Santino D'Antonio of the Camorra (a real- life Neapolitan version of the more infamous Mafia).
Having learned of John's one-man vendetta against the Tarasovs, Santino uses that opportunity to collect on that debt...in the form of his own sister's assassination. And thus begins a series of ever-escalating fights and shoot-outs. Not only with Gianna D'Antonio's vengeance- seeking bodyguard, Cassian. But, also, the henchmen of the double- crossing Santino...led by a seemingly mute lesbian tomboy.
Needless to say, Santino ultimately pays for his treachery. But, it comes at a tremendous price for John. Namely; permanent disownment by the CEO of the Continental Hotel chain (which provides neutral ground lodging for all globe-trotting hit men and women). Now, personally, I think John did Sir Winston a favor. I mean, if Santino was willing to stoop to having his own sister killed, just to become king of all organized crime in New York City, would he really have stopped there?
I don't think so. An ambitious narcissist, like him, would eventually have strove to become the only one sitting at the High Table. Perhaps, even new and sole owner of the Continental Hotel chain! And I think Sir Winston realized that, too. Why else give John one hour's grace with regard to the internationalizing of the open contract put out on his life by Santino?
At any rate, this cliff-hanger ending sets up the expectation that there will be a third and final chapter. One that will hopefully further expand on the now twice-mentioned "impossible task." For example: did it involve the death of Santino and Gianna's father? If so, do either of them have any offspring of their own (legit or otherwise) looking to avenge their deaths at John Wick's expense? Most importantly of all; will John get his beloved Mach 1 Mustang back?
Until that third question is answered "yes," I only give this nine out of ten stars.