Not wanting to be left behind and forgotten in the “who’s first to 64-bit” battle, Intel has announced that new devices coming out with Bay Trail (Intel’s tablet chip platform) sometime in 2014 will have 64-bit support enabled. Unlike ARM, Intel doesn’t need a new ISA, because they were already using the same x86-x64 ISA of theirs, it’s just that the 64-bit parts in the new Atom chips have been disabled, to lower costs.
Intel does this all the time with other features in their chips, too. For example, the Core i5 chips may support a certain feature, and it will be available in Core i3, too, but it will be disabled, so you’ll never be able to use it. This decreases complexity somewhat for them, since they don’t have to make very different chips for each price range, and therefore it reduces cost.