"64-bit" is simply a marketing buzzword based on the "bigger is better" school of thought. Apple did it with the first G5 cheese graters, and now they're doing it with phones. Yawn.
I don't understand all the brouhaha over this. Either the CPU is 64-bit or it isn't. Whether or not that makes any difference is 100% MOOT. If they called it 32-bit when it's a 64-bit CPU, it would be fraud so WTF is the big deal that they're calling it a 64-bit CPU when it IS a 64-bit CPU???
Until this Qualcomm marketing executive made this claim, I didn't pay one bit of attention to whether the CPU was 64-bit or not. I couldn't care less. But because the competition is making a big deal about it, now I DO know it's a 64-bit chip whether I want to or not and as I stated before, it makes a lot of sense for Apple to move to 64-bit even when it's not "useful" because it means iOS and OSX are once again on a level playing field so that it's easier to merge or partially merge them. Apple has been working very hard to wipe out all their 32-bit code in OSX and it's pretty obvious they will one day make it mandatory just as they've depreciated Carbon, etc. You can't blame them for moving into the future. Microsoft will have and has had a much harder time going pure 64-bit and frankly, it's caused them a lot of problems with incompatibilities due to a lack of 64-bit drivers and yet if you wanted more than a couple of Gigs of ram, you were screwed with the 32-bit version. How many years will it be before the iPad is capable of using 4+ Gigs of ram? They could do it next year if they really wanted to. They could move it to full OSX if they wanted to. Getting the CPUs in-line with OSX only makes sense in that regard. Whether iOS merges into OSX or OSX merge with iOS, either way the writing is on the wall. They will one day have ONE operating system for everything. Whether that's in two years or twenty years, it doesn't really matter. It's best to move things in that direction sooner rather than later to keep options open.