According to Bloomberg, Google is "considering designing its own server processors using technology from ARM." This move could endanger a big portion of Intel's revenue in the future, as Google alone accounts for almost 5 percent of it. Google is one of Intel's biggest customers right now, considering just how many servers Google has and how many datacenters it keep building, and Google has even put Paul Otellini (former Intel CEO) on its board years ago. So Intel and Google have a pretty strong relationship.
On the other hand, it was really only a matter of time before Google would start building its own ARM-based servers, because ARM allows them to build much more customized solutions based on their architecture, while with Intel, they still have to accept pretty general-purpose solutions for their servers.
By building their own servers from the ground-up, Google can make its servers more efficient in how they work with each other, since everything should be a lot more integrated, but also more efficient in terms of power consumption. One of the main attractions of ARM servers is that they can be more efficient than the big server chips, especially if the tasks they're running on those servers don't need big server chips. Google has been a great advocate of "going green", using as little energy as possible for its datacenters, and by also combining that with using renewable energy, too. Plus, it helps them get lower electricity bills every month, so why not?
So you can see why building its own chips makes a lot of sense for Google, at least on the server side. But the question is, will Google only ever make server chips, or will they later start making consumer chips, too, for their Nexus or Motorola devices? We've already seen that Google was interested in making more customized chips for Motorola devices, with the X8 platform. I'm sure they have their own ideas and plans for how chips should work in mobile, much like Apple does, but perhaps they can't yet demand too much customization from companies like Qualcomm or Nvidia, because those companies have to serve everyone, not just Google.
Perhaps one day we'll also see a custom CPU from Google, based on the ARMv8 architecture, that comes with a GPU from either ARM (Mali) or Nvidia (since they promised to start licensing their mobile GPU's starting with Kepler, too), unless they decide to make their own GPU, too, but that seems like a much harder task, and I doubt it would be necessary from their point of view, anyway. Such an idea might take a couple more years before it comes to fruition, though, if ever.