Let's see...
-ARM is trying to get into laptops and, eventually desktops, while x86 is trying to get into ultra mobile (tablets and phones) score: 0:0
-ARM has failed to get into said market, while x86 can be found in tablets. score 0:1
-ARM dominates a market where operating systems are becoming more and more complex with an ever increasing selection of apps, something that x86 excels at, but still lacks the power efficiency in order to consolidate itself in that market, for now. To put it simply, software for ultra mobile devices is becoming more like the software for laptops and desktops, and x86 is all like "c'mon baby, grandma needs a new pair of shoes!", while ARM is like "Hey man, slow down brah, I can't keep up...".
Score: 0:1
Overall score ARM 0:2 x86.
Looks like x86 is here to stay, from where I'm standing.