Air Jamaica applied for IAH-MBJ two years ago and had no trouble getting approval. It took about a week. They re-applied last Thursday, and I expect similar results...where did you hear they're having problems getting approval? The reason they never came was because the company bailed out; no regulatory body was stopping them.
BTW, AJ plans for five weekly A320 services to IAH starting June 7th, subject to change. I was surprised to see DEN on there, but either way they haven't applied for service there yet so nothing is final.
BWIA has had IAH service on their mind since October of 99. I can't wait to finally have them here in October. Their relationship with CO is pretty limited, but IAH is gaining popularity as a caribbean gateway. There's also oil involved. BWIA is set with UA as their American partner (hence IAD), so i don't think their serving IAH is alliance related. As far as I know they still plan to serve ATL. Flight 750, a 737-800 flying POS-BGI-ATL is still on Sabre, operating three time a week.