Threshold is expected to be Blue's sequel.
ZDNet reports that the Spring 2015 wave of Windows-based releases is codenamed "Threshold," which is derived from the planet of the same name in the original Halo released back in 2001. Unnamed sources reportedly said that Microsoft Executive Vice President Terry Myerson actually mentioned the Threshold codename in a recent internal company email about his plans for a unified operating system engineering group.
So far the unofficial Windows roadmap reveals that Windows 8.1 and Windows RT 8.1 will receive an update in Spring 2014 (v8.1.1?). This will also be the time when Microsoft releases the "Blue" update for Windows Phone, catching it up to v8.1. After that, Windows 8.1 will reportedly receive another big update in Fall 2014, v8.1.2 perhaps, around one year after Windows 8.1 originally went live.
Based on information provided by unnamed sources, Microsoft is planning to shift its major releases to the Spring. The "Threshold" update is likely similar to the "Blue" wave of updates, and is scheduled to take place in the Spring 2015 timeframe as previously mentioned. Included in this update is reportedly Windows 8.2, Windows Phone 8.2 and Xbox One. This numbering scheme is merely speculation given that Microsoft will likely want to keep Windows variants on the same level.
Right now Windows 8.x, Windows Phone and the Xbox One OS share a common Windows NT core. But by Spring 2015, Microsoft is expected to have already merged Windows RT and Windows Phone into one platform. We saw this coming with the introduction of larger screens in the latest Windows Phone update. The company is also expected to release a unified developer portal in Spring 2014, followed by the unified storefront in Spring 2015.
In addition to the common developer toolset and storefront, Threshold will reportedly add another level of commonality across all Windows platforms by supporting the same set of "high value activities." These include "serious fun," meetings, tasks, research, information assurance and IT/Dev workloads. Steve Ballmer mentioned the concept of high-value activities back in July when he announced the company's re-organization.
"We are going to focus on completely reinventing experiences like creating or viewing a creative document and what it means to communicate socially at home or in meetings at work," Ballmer said. "We are going to immerse people in deep entertainment experiences that let them have serious fun in ways so intense and delightful that they will blur the line between reality and fantasy. And as we develop these new experiences, we will also support our developers with the simplest ways to develop apps or cloud services and integrate with our products."
The company is also reportedly working on a Siri competitor called Cortana, which is a fictional AI in the Halo series.