I actually bought the Samsung Series 3 Chromebook(AKA the $249 ARM one) and I can say it's well worth the money. It won't replace my main computer, no, but it does everything I use my desktop for except for three things:
1) Gaming
2) Burning discs
3) Programming/web development
Practically everything else I need a computer for, it does. It has Google Docs(i.e. Word, Excel, PowerPoint). It can run 1080p YouTube videos seamlessly. It has Flash support, so I have no problem browsing the web. And there's an extension that can handle some of the less complex Java applets. It has a built in Remote Desktop service(via a Chrome extension, comes pre-installed). It has a webcam and camera app. Not to mention this thing is FAST. Boots in about eight seconds. Resumes in less than a second and a half. Did I mention it comes with a 100GB of Google Drive storage for two years? It doesn't have any moving parts, and is absolutely silent. And the battery lasts about seven hours. It's amazing.
It doesn't do two things, though:
Music streaming services don't run too well(Pandora/Play Music) if you're doing other things. Better to use your phone for it.
Netflix support isn't there yet. It's been promised for Soon(TM).
With phone tethering, the whole argument about it being useless without the internet is a bit of a moot point. There's offline Google Docs regardless.
Highly recommend it to anyone wanting a cheap laptop.