Honestly Vipre, I don't think that would be necessary. There are many actors/actresses out there, both boxoffice names and not, with great talent and skill that could play these roles tastefully and faithfully, and I personally believe that if the director and producers cast the right people carefully, that this project could be a success. Then again, that's just me.
Matt Damon as Capt. Kirk might actually be a good choice. Keep in mind I said might. It all depends on how well he takes to the role, and how much research he does on the character. Knowing professional actors who take their trade seriously, not only will Damon be watching all the TOS episodes over and over again, same with the first 6 movies, he'll also get in touch with William Shatner and other surviving members of the cast, trying to get as much information about the character of Kirk to most effectively recreate the character to the best of his abilities.
I wonder though if Johnny Depp would ever be right for a role in this movie. His qualifications as an actor are rarely ever matched. He is truly a character actor, virtually transforming himself into the character he portrays, and if you really pay attention to his films, rarely are any two different characters of his remotely alike.
I think, if done tastefully, and decisions made carefully, this could be a success. Only time will tell.