Which Trek should they be faithful to? The original series? If so which season? The animated series? The incredibly dull first movie that was not very Trek like at all? The sitcom nonsense with the whales? The sloppy and ill conceived fifth movie? The first season of TNG or a latter season? The early Deep Space Nine or the latter Deep Space Nine? Voyager? Enterprise?
For me, I wouldn't take that direction. While I would no doubt be faithful to all the Star Trek's that have come before it (Will be hard for Enterprise), the direction of a new Star Trek wouldn't be restricted to what one series or movie did. I would create a Star Trek so that it could be it's own thing, and one idea that I've always had in mind when it comes to making a new series is usually met with "That would never work" and "Star Trek is about humanity!". Can you guess what my idea was? It's a pretty simple and we've seen it on some occasions in the show.
I also think being faithful to Star Trek as a whole should be pretty simple to. It doesn't have it be about just one thing. It can be about a lot of things. I think Star Trek is best when the writers come up with interesting ideas and just go for it. Whether they're outrageous or simple, Star Trek has the capacity to tell them without seeming to be un-Star Trek.