I think they may well do Horse and His boy, because storywise, it's one of the best, and gives them a great opportunity to do something very different setting-wise to Voyage and Silver Chair. And Aravis is a fab character.
But I do think we'll be very, very fortunate to get all seven, and particularly The Last Battle, which is absolutely fraught with theological difficulty and controversy and would be about as CGI heavy as it could possibly get. And poor Susan!
I'd love to see it, but I think I would probably be disappointed by it and maybe even a bit ticked off by inevitable changes. Although the existence of the noble Calormene soldier inside the stable/in heaven could work very well with modern sensibilities.
My favourite line in all the books comes from the Last Battle, and I doubt it would ever make the screen - When Lucy says, in response to the realization that the stable is bigger on the inside, "In our world too, a stable once had something inside it that was bigger than our whole world."
I know some people hate the Christian underpinnings of the books, but stuff like that line makes me appreciate the other-worldly thrill of the Christian ideas about incarnation and so on, and even if I didn't believe it anymore, I still love that mystery. /random tangent.