In March 2012, Microsoft first revealed some information on the choices the company made concerning the minimal resolutions for Windows 8 Modern apps. While those apps could run on their own at 1024x768, Microsoft decided to raise the minimal resolution to 1366 x768 for an app to run in "snap view" mode, where two apps could run together.
While snap view does allow for Windows 8 to run two Modern apps at the same time, one of the apps is greatly minimized in this mode. In the leaked build of Windows Blue that was released on the Internet on Sunday, it was revealed that Microsoft has allowed for more than two Modern apps to work in snap view mode and that they don't have to have their look minimized.
One interesting consequence about this change is that the minimal resolution for Modern apps in snap view has been lowered in Windows Blue, at least in this leaked build, from 1366 x768 to 1024x768. This was first reported by McAkins Online, which shows this change in action in a YouTube video.
It's possible that Microsoft made this change to allow Modern apps in Windows Blue to work in snap view on touchscreens that are smaller than the minimal 10.1 inch display that are currently available for Windows 8 tablets. There are lots of rumors that Windows Blue has been designed to run on screens that have seven or eight inch touch displays. It will be interesting to see if Microsoft sticks to this new 1024x768 resolution for snap view in Moderns apps or if they will change it back for the final version, which is rumored to be launched sometime this summer.
Source: McAkins Online