As I predicted in my post dated September 02, 2011, I just received marvelous news that mobile numbers transfer between the three operators in Kuwait (Zain, VIVA, Wataniya) will very soon be possible, I was waiting for this since ever! The charge for number tranfser is KD5 and the whole process takes no more than 24 hours.
I will get you the full details like how, where, and when customers can transfer their phone numbers.
Note: Below is a poll we are conducting to see which of the three operators (Zain, Viva, Wataniya) is the one that most people would like to transfer their current numbers to.
Update: I read on the paper that numbers transfer will begin by end of April 2013.