The crazy part is how many 'unknowns' (relatively) there are in the final cast
I'm glad the cast is filled with relative unknowns. When Star Wars Ep. IV came out, the only recognizable face among the leads was Guinness. The casting director's decisions worked to the story's advantage since they avoided causing a disconnect in viewers. Viewers were left to immerse themselves in the story.
Imagine if Brad Pitt had been hired to play one of the leads in Ep. VII. Some viewers would likely sit in the theater and think to themselves "
Oh look, it's Brad Pitt... he was awesome in Kalifornia... his wife's pretty hot... I hope Fury is good... man, his hair looks awful...."
Casting unknowns removes that risk (while introducing others, of course).
He is a good director, he did a bad ass job with star trek, not sure who else you would pick who can do a way better job than him?
Abrams is a scene guy. He's great at composing scenes that impress with action and/or special effects (e.g. Star Trek). He's also good at creating short-term suspense (e.g. Lost). But he's far less talented at building a compelling story arc. That's why Lost petered out quickly. Abrams lost focus on the arc.
Star Wars has a huge arc. George Lucas sucks in many ways, but his arc for Star Wars was brilliant. Abrams has yet to show the same degree of skill, creativity, and finesse.
If I were a studio exec or producer, I would trust him to write/direct an action flick. I would not trust him to write/direct Lord of the Rings or the Harry Potter series.
For Star Wars, I'd get excited if Peter Jackson, Guillermo del Toro, Alfonso Curaon, or Christopher Nolan were penning the script or directing the film.