Yeah, I wish they would have done better vehicles for Beckinsale AKA "Selene" ... great character, but just marginal movies after the first that continue to sink lower. Anne-Moss was great as Trinity. It should be obvious at this point that the female star has to actually be believable and a decent actress. [Heck, getting back to Underworld -- the best part about the movies, aside from the styling, are the quality actors that had put into them at first... Michael Sheen, Bill Nighy, Derek Jacobi. Heck, Charles Dance shows up in the 'second series' of movies. These are quality actors that can push the material, but they need something to work with.]
I really liked "Salt" a lot although they never seemed to figure out how to make it a franchise and released multiple endings. Jolie was good in the role, esp with it being unclear of what her real background was for much of the movie and the subplot about her husband (which humanized her).
Did you ever see Haywire? Gina Carano was great and capable with the moves, she's kind of intimidating and makes it look easier to crush an opponent in the quickest amount of time possible. Unfortunately, she couldn't act well (better than Keanu, but that is not saying much) and the plot is kind of "cold" versus emotionally engaging, so the movie never went anywhere really. Maybe proves the point? Or maybe it's important to somehow have a female action star who still feels "feminine" in some way -- and what does that mean exactly?
I can't guess the quality from the trailers. Theron fits the bill in being a great actress and can handle physically challenging roles, so I guess it comes down to the writing and directing. I would like it to work; I fear it won't.
Anyway, female spins on previously male-oriented concepts can work and allow exploration of differences.
I lean more with you guys on a female James Bond, I kinda don't see the point. Just create a new franchise, everyone will "get it" if you want to go that route.