I usually don't really like Hans Zimmer's work, especially on The Dark Knight trilogy, which I feel had a score ill-suited to the character, and which made me wish Danny Elfman had just been brought back to do the score, as was rumored online during the lead up to the release of Batman Begins. I've heard very little else from Zimmer that I liked, save for maybe his score to The Lion King (the original, and not the live action remake) and Interstellar, which had a fantastic score.
ALL THAT BEING SAID,
I would absolutely KILL to see Zimmer take on Star Trek, and here's why. If Giacchino is the modern John Williams as many claim (and I agree with this assessment) then Zimmer is definitely the modern Jerry Goldsmith. From his use of powerful percussion to his fondness for synthesizers, and even his innovative approach to science fiction film score (Aside from Goldsmith, Zimmer is the only one to utilize a friggin' Pipe Organ in his score for a sci-fi film, in this case Interstellar) Zimmer is the obvious choice for a Star Trek film now that Goldsmith is gone. I'd also KILL to hear Zimmer do a cover concert of the theme to Star Trek: The Motion Picture, complete with his signature style as mentioned above. I truly believe Zimmer is WAY more suited to Star Trek than Batman, and he is more suited to Sci-Fi in general than any of his other work.