I'd say the impact would go the other way, if at all. Disney has certainly noticed that Star Trek
has been successfully resurrected as a movie franchise by recasting the main big name characters with young, pretty actors. Star Wars
is more or less in the same boat, with a mismanaged movie franchise that needs some brand rebuilding. Same disease, so why not the same cure?
I would not at all be surprised to hear Disney is recasting Luke, Leia and Han to be about the same age as of ROTJ (25-35) and the sequel trilogy will deal with those characters after the death of the Empire. Even without Abrams' example, that's the most obvious route to making big mountains of money.
Most of the potential audience doesn't have emotional investment in the actors reprising the OT roles. There of course will be fans who react to recasting just as some fans reacted to anyone but Shatner playing Kirk, but as we've all seen, that had no impact on box office success and the movie turned out just fine creatively, too.
However, there is the potential for action-fantasy-movie overkill in all this.
I'd say the lower-profile superheroes like Guardians of the Galaxy
are in far more danger than any non-superhero based franchise.
Do you guys think a star wars reboot will be as good as star trek 2009?
Apples and oranges, but Star Wars
has the edge in the movies because it was originally made for movies - visual, visceral, emotional. Star Trek
was made for TV - emphasis on characters, themes and ideas - so it will always be a worse fit for movies.