I agree with the sentiment here - I wouldn't wish this casting job on a dog, because we know fandom will explode no matter who is chosen.
And a case could be made that there really is no need to cast several of the TOS characters here. According to the current information, this film is supposed to take place prior to Where No Man has Gone Before, either during or around the time of Kirk's first mission. Based upon the crew as seen in Where No Man, therefore, Uhura, Chekov and McCoy could and even perhaps should be omitted. (That said, of course, there's never been any canonical explanation for why Piper was CMO in Where No Man; the novel Strangers from the Sky suggests McCoy was on leave for whatever reason. And there's actually some retroactive precedent if you look at Beverly Crusher being temporarily replaced by Pulaski in TNG). Of course having Chekov established as being a crewmember before WNM in a canonical prequel would address the continuity fart in Wrath of Khan.
Having said all that, however, this film once again is not intended for "us". It's intended for people who perhaps haven't seen a Star Trek film since they retired the original crew back in Star Trek 6. Or perhaps people who have never bothered to see TNG, etc. but who still know the TOS originals. So they expect -- continuity be damned -- to see the classic characters. And that's what Paramount plans to do.
The only problem is that the prequel is gonna face the same jackpot ENT faced, with some of the more vocal fans confusing "canon" with "fanon". An example were all those who claimed up and down that ENT violated canon by having T'Pol become a member of Starfleet because either a novel or fan assumption was that Spock was the first; when TOS came out on DVD it was reported in this forum that someone went through the whole series and the movies and found no on-screen reference to Spock being the first Vulcan in Starfleet (the first to join the ACADEMY, perhaps). I'm expecting similar complaints if Trek XI takes place before Where No Man and features McCoy, or puts Sulu on the bridge instead of down in hydroponics or whereever he worked in WNM. Fans and novelists have spent more than 40 years "filling in the blanks", and as the reaction to some aspects of ENT proved, people get upset when "official" Trek doesn't jive. I've already seen a complaint that the film isn't going to follow the storyline of Vonda McIntire's "Enterprise: The First Adventure", for example, thereby rendering it utterly un-canonable, the same way ENT rendered Starfleet Year One completely moot, upsetting fans of that book/prospective series. And fan debate still rages over the Rhiannsu books, which diverged so much from on-screen canon that Pocket Books had to add disclaimers to the reprints.
Cheers!
Alex
