Ubuntu Light, like all versions of Ubuntu, is still a desktop operating system. By desktop operating system, I mean most of your data is stored on the actual device. Though my netbook may be mobile, my files are still physically stored on the device, and it is this device-centric factor that makes Ubuntu Light different from Google Chrome OS, which takes a different approach. On Google Chrome OS, barely anything is stored on the actual computer, because most of your documents and mail is hosted online in Google's servers. In other words, while Ubuntu Light is an actual operating system with applications and a desktop, Google Chrome OS is just a web browser. Unfortunately, making the decision between these two approaches will not be easy.
There are a number of advantages and disadvantages to both device-centric and Internet-centric computing. With device-centric, where your information is not stored on a centralized server, you get the benefit of always having access to your data. Lack of Wi-Fi or 3G will not put you in a dead zone as far as productivity goes. Furthermore, there are still numerous applications that cannot be run in a web browser, whether it be an actual word processing program (Google Docs is not there quite yet) or the terminal (for all those developers out there). However, with most of our services moving online by the boatload, these advantages become less and less applicable, and this only adds to the fact that mobile computing on a device-centric computer is only helpful when you have the device on you. With an Internet-centric device, however, your data is accessible anywhere, and it is very likely both your computer and your data will not crash or be lost as often as it would in the hands of the normal consumer.
Unfortunately, visibility is limited in being able to predict what side of the scale future computing will fall on, though it is most likely to strike a balance somewhere in the middle, but what is definitely apparent is the fact that questions about the very concept of mobile computing will soon change what we know and call our desktop computer. All we can be sure about, though, is that the variety in design and concept concerning mobile computing software will only make it that much better for the consumer in the long run, so prepare for an exciting and mobile ride!