I'm sure I have watched, and enjoyed, far worse than whatever this movie will turn out to be. I must admit that I do get a little twitch in the corner of my eye when I see ScarJo playing the major. It's not like Hollywood has a shortage of talented Asian actresses, to play a tiny Japanese chick for crying out loud! She better do a damn good job (which she is capable of) or it will be a sore spot with me.
As for how deep this movie gets into the classic GitS themes of asking questions about the limits of humanity and consciousness, and how massive technological integration with our minds/bodies affects society, I still hope to see those things drive the plot. However, given the amount of money it costs to get ScarJo, I'm pretty sure the plot will be driving them between scenes of spectacular CGI-laden butt-kickery. I think I'm OK with that. It may not be exactly the same as the anime, but I hold out hope that it can incorporate some of the same themes...and awesome butt-kickery.
I understand that when a 'smaller' property gets released as a big-budget Hollywood film, there is a certain amount of change that is GOING to happen. No one lays out $100 million and says, "re-make that cult classic and stay as close as you can to the source to make the current fans happy." They say, "re-make that cult classic, but change whatever you need to in order to make sure it makes us $200 million." It is a business, after all, and I understand wanting a pretty safe bet when you put up big-budget money for a film. Heck, if it was my $100 million, I might cast a white lady that will draw in fans with her name as well! Of course, I might have gone with Helen Miren. She's just so classy!