Well you could always connect Shatner to the project or bring in another star actor to play a new character such as RIker and Troi having a kid who is played by" young hot middle 20's sexy up and coming movie star."
Jason
I'm not remotely convinced shatner is the answer either. It's general audiences we need here. Don't get me wrong, the presence of the shat wouldn't hurt the film (unless it was handled badly like in generations) but is it enough to sell this movie to millenials who've never seen a single episode of TNG? I doubt it very much.
I'm all for a crossover of some type. In a way it could be a glorious last roll of the dice for this series of movies, but I think Stewart/Shatner need to be extended cameos at the most, not the main draw, the epic scope of the story needs to sell this, not a 77 and and an 87 year old. Christ, the guy could be potentially be 90 by the time this sees the light of day.