I think this is exactly it. Perhaps they do have a specific usage in mind that they're aiming for, but I bet they'd be taking these same steps regardless.
True, though nominally the same partner. Motorola was the M in AIM, though yes, IBM did the heavy lifting. (Remember Motorola made a Mac clone? How weird.) And the situation wasn't as dire then.
Least grandiose theory I can come with: two ARM cores in the Watch, one big, one small, with different instruction sets, for active/standby modes.