It has been mentioned elseware, that in order to avoid racism HHB would be necessary if they were going to make LB.
Think about the calormens. If HHB is not made, moviegoers will only see the calormens as bad, evil people, people with arab/african looks. Could be construed by some as racist. However is HHB is made, we see the good side of Calormens in Aravis, and her friend, and even to some extent the old fisherman who took Shasta in.
Regardless, I would love to see HHB. I think it is a thrilling story, that could hold its own quite well.