ARM does the R&D for companies like Qualcom, Texas Instruments and NVidea to make the ARM processors with their own spin on the initial design.
The bad news for ARM is that they don't have the cash to support an R&D effort against Intel. Right now, sure you can argue that ARM can stack up against Intel and survive. They may even continue to own the high volume, low margin of smart phone processors for the next few years. I figure it takes Intel about five years to lap it's competition in the R&D race. Right now everybody is waiting for Intel to "Catch up" to ARM's power envelope. ------
Only Qualcom 'tweak' the ARM core, Nvidia and TI use bog standard cores (Nvidia project denver aside [64bit ARM core]).
R&D wise, ARM has plenty of cash (more importantly, people) to 'compete' with Intel. According to the link below, even with tri gate Intel aren't going to compete on power consumption (15W for a table chipset in 2015!).