Google Chromebook is all in the talks.
There are small cheap ones around $200, such as the Acer C720 Chromebook
and there are big expensive ones (≻ $1000), such as Google Chromebook pixel
I wondered whether it is useful for programers on the go, running unix shell bag, coding python, web dev, run database, emacs, etc.
short answer: no.
am looking to buy a laptop.
Apple's out, because the price/meat ratio is about 2 times higher than competitors.
so, that leaves Chromebook and normal Windows laptop.
Can you install Linux on Chromebook?
yes, but not the normal way.
You have to go thru unsupported hackery process such as turn on developer mode, which adds 10 secs to boot time, then other hackery process to get going. Or, another option is booting up with Chrome OS and run Linux on top, again, not good.
you can read about the complexities here:
Running linux on Chromebook, tech detail https://wiki.archlinux.org/index.php/Chromebook
Horror stories of running linux on chromebook. After a ChromeOS update, your Linux is screwed. Good luck recovering your data. October 19th, 2013. http://ubuntuforums.org/showthread.php?t=2181898
some possibel choices: