Hrm.
To be honest, I like the idea that some movies feature scenes shot in locations that have not appeared before. I like new takes on traditional characters that present them in new ways.
Done right, it really adds to a movie. Done wrong, we get characters like this:
http://ironman.wikia.com/wiki/Dr._Wu
I would like it if the politics of casting / location were less of an issue and people were encouraged to make decisions based on what works for the story. This would mean Hollywood would need to reduce the overall budgets for films, because what drives most decisions is the bottom line.
Many of the movies I love the most that are considered mainstream were shot on minimal budgets and not expected to be box office successes. In most cases, they had very diverse casts in genuine, authentic roles people could relate to.