'Bolt' could be the next-gen Chromebook Pixel, with a Haswell CPU
Google's chromium logs show a plethora of things - many of them indecipherable to everyone but an experienced developer. Occasionally, something will spike interest, such as new devices or upcoming features on the OS. In the past, multiple references to devices such as 'Puppy', an ARM-based Chromebook, and 'daisy_spring', a rumoured update to the Samsung Chromebook, have been found. However, the device that has popped up recently takes the biscuit.
The device is codenamed 'Bolt'. A post on Google+ by Chrome OS developer Kenny Strawn reveals that files referencing the device show that it has a backlit keyboard, a touchscreen identical to the Pixel, and a light sensor that is also identical. We also know, thanks to Chrome Story, that the device has 4GB RAM and a Haswell processor.
While it looks likely that the device is a followup to the original Pixel, we cannot know that for sure until Google announces the device, or it leaks in more detail. However, one thing is for certain: you should be keeping tabs on this device.