The news that Dubai World, one of the stalwarts of the Dubai economy, is potentially defaulting on its debt, is a huge blow for Dubai's reputation. It highlights the severity of the emirate's financial crisis, the true depth of which has been hidden from investors by a screen of government support, largely funded by Abu Dhabi. The news will send shockwaves throughout the Middle East, and beyond, and while the situation is still unclear, we try to decode the news and assess its key implications.