A work in progress
Now, as for how the apps themselves work in the Chrome browser, we tried the official Twitter app, and amazingly enough, it works almost flawlessly. Until it doesn't, anyway. In our testing, we were able to browse our Twitter feed, post tweets, view pictures - all the usual stuff. The app ran fairly smoothly on a late 2012 MacBook Air, and it looked good, although the typography was a little light compared to the regular desktop site, so some things were hard to read. It responded to mouse clicks as if they were finger taps, and even let us scroll up and down using OS X's two-finger scrolling.
We did encounter one hiccup though, when ARC Welder ran into a problem and forced the app to close. It is beta, after all. But still, it's neat to be able to run apps intended for a mobile device on a computer.
While it would be easier to run your Android apps on a tablet or smartphone as they were designed to be used, ARC could be a huge boon for Chromebooks and eliminate the web limitations of Chrome OS. What's more, this could be the starting point of a rich Chrome app ecosystem.
Where does ARC go from here?
On some level, ARC seems a little out of place in a world where native mobile apps are the norm and web apps fill most compatibility gaps.
Still, it's unreasonable to expect all developers to hop on the web app train, and for our Chromebook-using friends, having an additional source of apps could be a godsend. Just don't expect it to completely remake the app landscape anytime soon.