Xbox live definitely works over here but you aren't supposed to transfer your existing profile to a new country - and as such you can't pay for your continued subscription with a M.E. credit card or one that the mailing address is a M.E. address. So you either lose all your gamerscore, friends list etc, or else you need to keep a US credit card active with a US mailing address, or use someone else's card back home to pay for the sub.
I wouldn't be bothered dealing with converters for PAL/NTSC or voltage or whatever if I was you, those things are so damn sensitive to dust and voltage fluctuations etc I blew up my English one only a few weeks after I got here ... take my advice, pull your hard drive off and bring it with you, sell the actual machine on ebay before you come out here and buy a new one when you arrive, they're cheap enough (Dubai duty free AED 800 for the basic model I think).