No-one else can be Apple. It's questionable how long Apple can continue to be Apple. They got to own a stack because they started way ahead of the competition and haven't slacked or hit any technological walls. Upon the inevitable moment they lose momentum, the clones baying at their heels will eat them. This happened before, with classic Mac before the Jobs renaissance.
As for Nokia, the market has reached a point of consolidation on standards comparable to the collapse of competing computer types in the early 90s from Atari, Commodore, Acorn, Amstrad etc to PC and Mac and nothing else. So they can either sell hardware or die.
It's interesting to note that Apple was in a very similar position back in those days. They were dying, and made the decision to buy NeXT to change OS directions. The primary consideration was the OS, not Jobs; they were apparently very close to buying BeOS instead. Jobs being the catalyst for strategic change happened to be a pleasant surprise. He didn't even become the CEO of Apple again until much later.
So, to be clear, even Apple wasn't Apple. Apple didn't reinvent itself. Apple bought NeXT to try to go a new direction; that is, innovation was acquired, not developed in-house. Looks like Nokia would be forced to do the same, judging from the mood around meego (or in this case, simply partner with an outsider).
As for Nokia, the market has reached a point of consolidation on standards comparable to the collapse of competing computer types in the early 90s from Atari, Commodore, Acorn, Amstrad etc to PC and Mac and nothing else. So they can either sell hardware or die.