Google is working on Chromebooks based on high performance ARM SoCs and Intel's Bay Trail technology, according to recently surfaced Chrome OS source code. Some reports are suggesting that Google is pushing its OEMs to create Chromebooks with ARM technology, but the recent leaks appear to show that the company has devices with both in the works.
At this point, it looks as though there is already talk of at least one of Google's OEMs working on a Chromebook running Nvidia's Tegra 4 chip. As you may know, the Tegra 4 brings together a quad-core ARM Cortex-A15 CPU running at 1.90 GHz, with Nvidia's 72 core GeForce ULV graphics. This kind of power will be more than suitable for Chrome OS, as it can easily handle high res Android tablets with a display resolution of up to 2560 x 1600 pixels.
The leaked code is also suggesting there are more powerful Chromebooks with Intel SoCs on the way as well. The report points at Chromebooks with Atom Bay Trail SoCs under the codenames "Bayley Bay" and '"rambi." It mentions a Chromebook with an Intel Atom E3845 SoC inside, a quad-core x86-64 CPU running at 1.91 GHz. Although they have a very similar form factor, the Bay Trail option does hold a specific advantage over the Tegra 4 in that it's capable of supporting 64-bit and more than 4GB of system memory.