Chromebook as a basic web development machine?

I'm planning to get a Samsung Chromebook (the one that's currently out today) as a simple machine for writing documents in Drive and browsing the web (basically as a "tablet" that isn't touchscreen and with a keyboard). BUT I also want to develop Chrome packaged apps, which I believe are written in HTML/CSS/JS. Since web dev is pretty "free" and doesn't really need a fully fledged IDE, and can be done with a simple text editor and a terminal window, is the chromebook a viable (as in minimally sufficient) device for this? Does Chrome OS give full access to a terminal window and it's tools like VIM, nano, etc.

What's worrying me is the limitations of the OS. I know it's built on top of Gentoo Linux, but how much of Linux is actually accessible? And how limiting the ARM processor is.

ALSO, while we're on this topic, is the chromebook worth buying at $270 as a NORMAL browsing machine? I've heard many things about the processor being too slow, but even more accounts saying that the machine is perfect. What's your say? Thanks in advance!