It doesn't replace the OS, but all of the "viable for developer" parts of it come from running inside the Ubuntu chroot, so the fact that ChromeOS still exists is mostly academic in this context.
FWIW, I've owned one of the Samsung ARM Chromebooks since the week it was released and I've been running crouton for a couple of months now and it works really, really, well. I still use the ChromeOS side for very simple browsing (the Aura window manager is nice if all you need is the web) but switch over to the ubuntu/X11 interface often to do development work.
I have a few questions about running Crouton on my Samsung Chromebook:
1) Have you noticed any effect on battery life or boot time with the chroot environment in place?
2) Can I access Ubuntu CLI programs from the shell within ChromeOS or do I need to switch to the full Ubuntu window manager environment?
3) Any other disadvantages you can think of?
I'm not an expert on Crouton, but:
1) I haven't noticed any problems with battery or boot.
2) I use the cli-extra chroot, so no window manager. I have a tab open in ChromeOS with the crosh shell and switch back and forth to that.
3) None, so far. Before Crouton, I used the Secure Shell extension to ssh into a remote Ubuntu box, which was fine. Crouton makes it possible to have an offline development box.
If you are using the Chrome dev tools, is it still possible to locally edit and save files? Can you view local files with the ChromeOS browser and switch to the crosh shell, edit and reload?
FWIW, I've owned one of the Samsung ARM Chromebooks since the week it was released and I've been running crouton for a couple of months now and it works really, really, well. I still use the ChromeOS side for very simple browsing (the Aura window manager is nice if all you need is the web) but switch over to the ubuntu/X11 interface often to do development work.