A small, light notebook with a good battery for $300 is pushing into impulse buy territory for me, with the condition that it's not an enormous pain to install linux on. I will be watching closely.
What's even more intriguing is that you can now flush the firmware on the 2012 model and it becomes just a regular PC that you can install windows/osx/linux in the regular way with no faffing about. Hopefully the same will be done for these new models.
Arch on an HP Chromebook 14" sounds for $299 sounds awesome to me.
http://johnlewis.ie/pre-built-coreboot-firmware-for-chromebo...
Keeping them seems one benefit to dual OS (reusing the Chrome kernel). It's nice to be able to watch HD video without hiccups.
Not sure if that's fast enough, but at least it's better than the typical 20MB/s for USB 2.0.