In Gasol's case, it's a combination of BBIQ and basketball gifts. Deng was another guy who has a nice combination of these two.
I agree with Transplant. The more talented you are the easier it is to judge how much of a Bball IQ you have so it's hard to gauge these things. I'd guess that guys like Scalabrine, Nazr, Mike James, and Kirk Hinrich all have extremely high bball IQ's but it's hard to look smart when you're physically incapable of doing stuff a bunch of other guys can do.