Windows Blue isn't just a service pack. And it's not a precursor to some other version of Windows due out later this year.
Though word of its existence first leaked in August of 2012, there's still a lot of confusion about what Microsoft's Blue is and isn't.
Partially, this is due to Microsoft officials not saying a whole heck of a lot about Blue so far. That will be changing within the next couple months, as Microsoft completes initial development and delivers an expected public preview of Windows Blue, starting with client and server. But as of now, basically everything you've seen me and others blog about Blue has come from sources with varying degrees of knowledge about Blue.
The other reason for the confusion about Blue is it seems to be a codename for both products and a change in the way Microsoft builds, tests and releases software. (This same double meaning of the codename applies to Microsoft's Gemini. Gemini is the codename for the next set of Metro-style Office apps — Word MX, Excel MX, PowerPoint MX and Lync MX — as well as the work of the Office team to change how it rolls out new releases.)
Too many people are getting caught up in the weeds about Blue. Specifically, they are confused as to whether Blue is just another name for Service Pack 1.
It's not. But I understand how some would see it that way.
Read more at source:
What Microsoft's Blue is and isn't | ZDNet