From rumor to reality in three days:
Microsoft Edge: Making the web better through more open source collaboration
For the past few years, Microsoft has meaningfully increased participation in the open source software (OSS) community, becoming one of the world’s largest supporters of OSS projects. Today we’re announcing that we intend to adopt the Chromium open source project in the development of Microsoft Edge on the desktop to create better web compatibility for our customers and less fragmentation of the web for all web developers.
There are a lot of words out there that could be used as a new browser name. Keeping the old name could cause confusion.
Previously here:
Mike Cane's Atomic Supermen 
Why would keeping the old name cause confusion? The masses already know that MSFT’s browser is Edge. Keep the name and change the rendering engine.
Well, it’s been tied to Windows Update cycles in the past. Not everyone updates (I try not to because the effin updates NEVER INSTALL!). So some people might wind up having the old version and wondering why it’s still crap.