There is no good financial reason to change the name.
Can you imagine an Apple product titled "OS Y"? Or perhaps "OS XI"?
These options would be a logical progression, and quite frankly they suck.
I'm sure the good folk at Apple will update the name, when an appropriate marketing opportunity presents itself.
Perhaps after a year or two of convergence we'll see "Apple iOS" . . . . Nahhh, "OS X" is still cooler
Besides, after a few iterations you'd end up with "Apple iOS X", so why bother?
