I don't know how i feel about the casting for Han Solo, to begin with i don't want the movie. But does that mean i wont watch it? hell no.
It's hard to imagine anyone else playing Han other then Harirson, it's such an iconic character and actor. However Han Solo is not just the face, but the way the character carry himself. If Alden Ehrenreich is able to tap into the essens of Han Solo i don't think it will take me long to look past the differences. It would be harder if the movie took place between 'A New Hope' and 'Force Awakens' because we know what Han looks like in that period. It will be easier to buy him as a younger Solo.
I'm kind of glad they didn't go with Anthony Ingruber, sure they guy looks like Ford and sounds like him. But other then doing an Solo impression, would he be able to hold a movie on his own? and not just be doing a Han Solo impression for 90min.