Information on Windows Blue, the next major version of Windows, has started to leak out of Redmond recently. The first round of screenshots revealed a major NT kernel change, but Win8china has now published a screenshot from a recent Windows Blue milestone build that shows Internet Explorer 11 is being prepared for the update. Microsoft previously built Internet Explorer 10 into Windows 8, and it looks like the company is preparing to do the same with IE11 in Windows Blue.
There's no details on features for IE11 or availability to Windows 7 users, but a browser upgrade in Windows Blue seems likely given it will be a feature heavy upgrade to Windows 8. Win8china speculates that a Windows Blue preview version will be released for public download in the coming months, with IE11 for testing. Given Windows Blue will likely debut later this year alongside new hardware form factors, it's reasonable to expect Microsoft to start testing publicly by the summer time.
Microsoft has so far refused to comment on Windows Blue, but the company did accidentally confirm its existence in a job posting recently. Although most of the focus is on Windows itself, Microsoft is also working on a Blue update for Windows Phone and other services such as Outlook.com. The updates won't all launch simultaneously, but they're part of a broader push to harmonise Microsoft's software and services.