Google has been working for some time on a Tab Groups feature in Google Chrome.
We reported earlier on the development but back then all we had was just the context menu containing options to group tabs. A bit later Google gave is a look at what the UI would look like.
Now Techdows has uncovered the latest development in this useful feature, designed to address tab overload.
The latest change is that Google now has seperate labels for each tab group (Group 1, Group 2 etc), a name which we assume users will eventually be able to change.
The update has broken the ability to save and restore these tab groups, but Google is working to fix that in a future update.
The feature is currently only in the Canary build of Chrome. You can get the Chrome Canary from here.