Dubai also has The Observatory, on the 52nd floor of the Marriott Harbour, and Bar 44 (quite possibly the best bar in town) and Embassy on the top floors of Grosvenor House towers 1 & 2 respectively.
Haven't been yet but I understand that the new Jumeirah Etihad Towers Hotel in Abu Dhabi has a restaurant and bar on the 62nd/63rd floors - these should have a great view of the Emirates Palace and the Corniche.