ARM is not Intel is not ARM
ARM is a design house. Intel is a foundry and design house. Comparing ARM and Intel doesn't really make sense. What makes sense is to compare Intel processor design with ARM processor design. As someone who has worked with both Intel processors and ARM cores, both are excellent for the tasks designed; both design houses are top-notch.
The question that I see will be answered is whether having design and foundry people as one can produce a better (someone else can define "better") product. ARM has numerous independent foundries using their IP which has worked out quite well to date for ARM. However, as Intel starts moving into ARM arena, will the advantage of having chip designers being part of the same team with the foundry outweigh ARMs business model; which model will win out when it comes to creating greater power efficiencies coupled with increasing computing power.
In the end, power and efficiency boils down to who makes the best transistor ergo my money is on Intel even if ARM comes up with a better design.