Nothing is going to happen.
First, the vote wasn't binding, and the people in La Fortaleza are the non-statehood people (for the status quo, which is known as the "ELA": Estado Libre Asociado: "Associated Free State"), who have clearly stated their intention not to proceed on it.
Second, statehood didn't really win. Read the description again. In the first question, the status quo got 46% compared to all possible changes combined. What lost to statehood 33 to 61 in the other question was something similar to the ELA, but more independent. The questions were gerrymandered to look like people overwhelmingly support statehood when they don't.
Consequently, the Populares have no real mandate to pursue statehood.
I have lived in Puerto Rico for the last 8 years+, and the "statehood vs. ELA" is really the only issue between the parties, besides whose candidate is the bigger desgraciado sinverguensa. It's about evenly divided between the "statehood" PNP ("Pe-Ne-Pe") and the "ELA" Populares. Any time the statehood people look like they may be getting ahead, all the Populares have to do is form an alliance with the Independentistas, who favor a complete break-away, and who have about 5% of the people backing them, give or take 2 or 3% at any given time.
Even if the PNP ever got their way and we petitioned for statehood, as has been mentioned, there is no guarantee that the US wants another state. It depends largely on which states would be losing representatives from the fixed number in Congress: if they have powerful reps, it will probably get bogged down and die.
A couple of random thoughts:
Statehood is probably not a good idea for PR as most Ricans who have a regular job couldn't afford federal income tax coming out of their checks.
On the other hand, it would be a good idea for the US because this is a great strategic place for military bases. "Rosie Roads" naval base and the Air Force base in Aguadilla all but closed down when Ricans protested the bombing practice on Vieques. I used to live in Groton, Connecticut and the Submarine base there has only remained open because Connecticut always has powerful Senators (Weiker, Ribicoff, Dodd Sr, Dodd Jr, Lieberman, etc.) It's a sucky place for a sub base. The subs have to get miles down a river past 2 bridges that could be turned into impassible barriers by a well-placed bomb. Even after they get out the mouth of the River they have to travel a long distance in Long Island Sound before they can submerge -- they're sitting ducks. Also, Navy people hate being stationed there because the weather sucks.
Puerto Rico, on the other hand has huge deep trenches right off the coast. I have whale-watched from the beach across the street from my house.
The right answer to the wrong question is still the wrong answer to the real question.