Have you heard the one about the smartphone with the battery life that lasted as long as the ordinary phone? No of course you haven't, it's never happened, and that's probably why Intel has formed an alliance with Google on its Android phone platform. Currently ARM is by far the leader in mobile chips.
Arguably the mobile market has been bugbear for Intel for some time now; i fact its chipset which is a competitor to ARM, called Oak Trail, has only recently emerged.
Meanwhile the overall world market for desktops and even laptops is decreasing as more and more people opt for a tablet computer. It's no wonder Intel is looking to this market for its volume, it's probably the only way it can see itself having a long term future.
The scale of the task it now faces is considerable. To get a quick and easy understanding of it, just consider that there's an established force in the market which more or less owns mobile computing in the shape of ARM.
Consider now how difficult it has been historically for anyone else to gain a real toehold in the PC chip market, with Intel's dominance so long established. But that market's shrinking, and now Intel has to perform the same trick that it's prevented others from doing so efficiently- gaining a share in a market that's effectively someone else's property.