I would have liked to have seen Captain Sulu, but I'm sorry to say I think George Takei is too old now to play an active duty captain. Maybe he could guest star as an admiral once in a while. No, we should not get someone else to play Sulu. Same goes for all the prime universe cast, really. Maybe Michael Dorn with all the makeup, but it was made very clear in DS9 that he was never going to command, and at the end he was on his way to being Federation ambassador to Kronos. Which could also be an interesting opportunity for him to guest star.
I'd like to see the prime universe after the end of DS9, see the reconstruction after the Dominion War, etc. But it would have to be a new ship and crew. And I like story arcs. Sure, tell some one-short episodes also, but there should also be story arcs. Planet of the Week stories mostly bore me.