Star Trek 09 didn't make twice it's budget money back in domestic gross (going by the estimated $150 million budget figures - if it was lower, then never mind), and compared to other recent franchise pictures, even the worldwide gross was pretty small to average. It's made more actual box office dollars than any previous Trek film, but The Wrath of Khan was actually more profitable by making it's budget cost back 11 times over.
In order for ST: Into Darkness to be an actual success, it has to make a shitload of money. I have no doubt that it will do extremely well, the trailers look incredible. Just remember that generally a film's success lies more in how much of its cost it makes back rather than strict B.O. bucks. 11 times vs less than twice? Considering the price of IMAX tickets and the general increase in price of the average admission, the number of people seeing Star Trek 09 in the theater was actually a lot less than than the number who paid to see Khan first run. For Star Trek, that's not that much repeat business, whether it had to do with the opinons of the film, or financial status of the audience (the days of my seeing a film multiple times in the theater are long gone).
Without judging the film itself at all, let's not let the $257,730,019 domestic box office go to our heads. For these types of films, that's not all that high. Into Darkness needs to bring in HUGE numbers, Dark Knight numbers, if it really wants to be one of the big boys.
Into Darkness will tell us if there really is an interest in Trek or if the 09 numbers were bourne out of curosity.
Also: I'm not worried about having different directors, but I am concerned about there being some sort of consistent vision for the concept. Motion pictures may be a director's playground, but these franchises need to be producer driven. So, even if Abrams doesn't direct the third film, he and his people need to be in place as producers - and not just "in name only" like Tim Burton on Batman Forever. It needs to be something like the Bond series, where the producers allow their directors a wide arena to play in, are willing to take risks, but still keep to a certain criteria to make sure the characters and situations are recognizable. You can do this without getting stale if you let your creative people do what they do.