Its a quite accurate statement to say Apple is a founder. ARM originally stood for "Acorn RISC machine" and was developed internally at Acorn. When ARM was incorporated as an independent entity it was done so with Acorn and Apple as 40% owners and VLSI technology (at that time the sole manufacturer) as a 20% owner. At that time the name was changes to "Advanced RISC Machines". Apple had more than Newton in the big picture at that time including laser printers. The ARM610 was indeed developed specifically for the Newton, with a special MMU by ARM as one of its earliest projects. ARM cpu's (in many case multiple ones) are in every cellular handset I'm aware of in the last decade not just smartphones. ARM cpu's are being used by most of the next wave of startup companies in low power server design..look at Smoothstone for an example. And of course they are making serious inroads in Netbook design, both NVIDIA's Tegra and Qualcomm's Snapdragon are giving Intel plenty sleepless nights right now. The last ARM design I did put an ARM7n in every electricity meter...in other words our entire tech world is already built around this architecture.
The royalties on the older designs are tiny and not going to be affected by an acquisition, don't expect any significant cost changes to be noticeable at retail even if it were possible to renegotiate the royalty schedules. After some stagnation in the last decade where ARM struggled to break out of the the low cost embedded space the company is suddenly looking strong again and it could be quite possible that Apple wants to go this way as an insurance policy, because they fear other big stalkers might acquire a company they are increasingly strategically reliant on.