First of all, Microsoft Spartan will utilize some of the new UI design components that Windows 10 will have and are yet to be released to public. Due to this no one can’t exactly tell you what the new Windows 10 browser will look like, but here is a mock-up (from NeoWin) that gives you some basic idea of how the Spartan’s interface will evolve.
Interestingly, Microsoft Spartan will also support digital inking like no current browser does. Tom Warren from The Verge, said:
Spartan will include digital inking support that allows Windows 10 users to annotate a web page with a stylus and send the notes and annotations to a friend or colleague. Annotated web pages will be able to be stored in OneDrive that can be accessed by any browser across multiple platforms.
Another major feature in the new Windows 10 browser will be the integration of Cortana. You’ll be able to access Cortana search features from the new tabbed interface of Spartan. It does seem legit since Windows 10 (across all devices) will have Cortana integration.
One thing that is confusing many and i would like to clear here is that, Spartan is not going to replace Internet Explorer in Windows 10. Both, the new Windows 10 browser (Spartan) and the new Internet Explorer will be available on Windows 10. Users would be able to download Spartan across all Windows 10 devices, from the Windows Store.