Vger23 made a really eccellent post on the subject a while ago. I hope he doesn't mind if I repost it here:
"I have to admit, I didn't really want Khan. But, now that it's happened, and I've been able to process the reality of it in real-time...I see that it is an absolutely brilliant idea. It's brilliant for several reasons:
1. Love it or hate it or anywhere in between...it will intrigue the fanbase enough so that everyone will want to see how it gets pulled off. Some will go hoping to see it succeed. Some will go hoping it will fail. But we'll all go.
2. It's an iconic and recognizable character that could be explored much more deeply. In TWOK, even though Khan was iconic and evil, he was fairly one-dimensional. In "Space Seed" he was more of a gathered, arrogant, power-hungry superman with a deep intellect and a sense of romanticism. I think there's a lot of unexplored territory there.
3. As I mentioned earlier...it's a huge risk. That generates buzz and excitement...which (again) is what Star Trek needs in this era. That's what the last film did so well. The 2009 film was good, but not great...but what it did better than any other Trek movie was generate a buzz and get people excited. That's something the franchise had been missing for a LONG time. Khan is buzzworthy. There's no buzzworthyness about saying "Benedict Cumberdubmerbatch (or whatever) is playing a half-betazoid evil derranged terrorist bent on ruining the fabric of the space time continuum with his Dooberhickey device." Yawn. Just another forgettable bad guy with a random sci-fi motive for being mean to people.
4. It's a great marketing tool. The casual movie-goer doesn't give a $hit about having a "unique villian" (see Insurrection and Nemesis as prime examples of bad attempts at "unique villians." But, if there's any ONE Star Trek movie sub-title that just about everyone knows...it's "The Wrath of Khan..." and everyone knows that movie was considered the best one. It's recognizable, it's fun, and it will pique interest in folks who otherwise might have bought a ticket to another movie.
I think it's a great idea.
NOW, the pressure will be on the creative team and the actors. Because it's an "all or nothing" gamble. It will either be absolutely fantastic or it will be a horrendous disappointment. But, doesn't that sound familliar?? It was the same deal with re-casting and re-imagining the TOS universe for the first film. And, that paid off with the critics, general audiences, and most fans. So, this is the next logical step following that same philosophy."
"The future is in the hands of those who explore... And from all the beauty they discover while crossing perpetually receding frontiers, they develop for nature and for humankind an infinite love." - Jacques Yves Cousteau