The rumor mill has gone back and forth regarding whether or not Microsoft’s next-generation operating system — Windows 8 — might include a tile UI similar to the “Metro UI” found in the company’s Windows Phone 7 platform. The coming operating system, which will seemingly be designed for tablets as much as it will be designed for desktop and laptop computers, will likely stray from Microsoft’s current Windows UI, but exactly how it might stray is unknown. Tech blog GeekSmack claims to have uncovered several hints in a very early build of Microsoft’s Windows 8 that points to the possibility of an alternate tile-based UI of some kind. References to an “Immersive shell,” “tiles,” a dock of some kind and a notification system all suggest that Microsoft is indeed cooking up a revamped tile-based UI for tablets. While it is not currently believed that the tile UI will be Windows 8’s main interface, a secondary UI for tablet devices is certainly plausible. Hit the break for a few more screen grabs of GeekSmack’s findings.