Windows 10's oft-reported Spartan web browser may not just be a leaner, fresher substitute for Internet Explorer -- it could have a few tricks up its sleeve, too. Sources for The Verge claim that Microsoft's voice-guided Cortana assistant will be present both in the OS and in Spartan -- much like Chrome's "OK Google" feature, you can reportedly open a new browser tab and ask Cortana to look something up, whether it's a website or your flight itinerary. There's also talk of pen-based annotations for websites that you can share with others through the cloud.
The apparent scoop also supports details mentioned in earlier reports, including the existence of separate desktop and mobile versions, a lightweight, Chrome-like interface and the inclusion of Internet Explorer in Windows for the sake of compatibility. Whether or not you'll see Microsoft show any of this at its January 21st Windows 10 event is another matter. Neowin claims to have seen an early build of Spartan, and it didn't see Cortana -- while the assistant may show up, neither it nor Spartan itself is necessarily ready for the spotlight.
Update: CNBeta claims to have pictures of Spartan. They not only back the rumors of a minimalist browser with Cortana support, but appear to show off an OS X Yosemite-style dark theme for Windows 10 itself. If you regularly hop on the computer at night, you're probably going to be quite happy.