Abu Dhabi who have actually invested in companys and tech around the world that makes huge money, vs Dubai who wanted to be the Vegas of the mideast, but do it over a few years at a vastly higher cost. The problem being that its the first world that can afford to go to a Vegas type place, but the real vegas allows getting smashed, banging hookers, obscene behaviour and is already built and already popular aswell as being English speaking with more hospitable weather.
Dubai might be bigger, but its not finished theres not as much to do there and you can't really get away with the crap you can get away with in Vegas, which is half the reason people want to go somewhere like that.
The fact is the other Emirates will most likely cover the short term debt, 80billion debt in total isn't that much for all the oil coming out of the UAE. What are the two options, banks owing the new Vegas when its finished? Or more likely, someone like Abu Dhabi owning the new Vegas.
Then again Abu Dhabi is being run like a serious serious business and don't seem to throw cash away, some of the investing these guys are doing, Dubai, Brunai, has been ridiculous. Rather than learn how to make more money and invest sensibly, Dubai/brunai is just throwing it away on whims, expensive whims, that have cost them hugely.