The plan to separate arriving and departing passengers was announced late last year, but I didn't know it was that far along. I'm still having trouble visualizing how they'll do that.
Terminal construction has been going on for years, so it's hard to tell any more what construction is for what purpose. I attended a press event in August 2000 for the inauguration of the new terminal. All that was done at the time was the baggage-claim area. Things are still not quite finished 12 years later.
I am happy to hear about including the exit tax in the price of the ticket, though. Back when there was a three-tiered system (tourists, foreign residents, citizens) it would have been difficult, but now that everybody pays the same $28, just do it already.