We don't hear this one every day. It appears Microsoft has leaked their very own UI, with a new marketing video for the company showing two short flashes of a new interface that is consistent with what we've seen previously from the company.

Despite this, the quick shot of the device shows a major overhaul of the taskbar, a move which has not been seen in years. Winrumors reports that the new UI was outed in a marketing video for "Flexible Workspace" and points out that it could be concept art. Despite this, the UI seems consistent with what we've seen over the last few weeks.

The new interface depicts a clock in the middle of the taskbar, surrounded by text. Winrumors points out that in the video the interface is animated, so it's unlikely to be concept art at this point. In addition to this, a video posted by Microsoft last week shows the new flattened task bar button styling (pictured below on the screen in the background), which matches up with the video posted today.

A new build of Windows 8 leaked today -- Build 7927 -- just ahead of Microsoft's BUILD event for developers in September, where the company is expected to unveil Windows 8 and make available beta bits and devices to attendees.

Update: And despite the reports around the Internet that this is a refreshed UI within Windows 8, WithinWindows (currently down as of writing, possibly due to heavy traffic) has stated that it is in-fact, Rainmeter!