Home windows 10 may ship regarding desktops later on in 2015 in addition to there is each and every chance the way the phone edition will get to around the same time frame frame. Unfortunately, Ms isn’t getting anymore specific compared to that at this time

The great news is that after it'll fully launch it'll be available for any year just like a free update to present Windows products, including individuals running House windows Phone 8. 1. For those who have the Windows Phone 8. 1 it is possible to get Home home windows 10 onto it before the season is away.

Which reasons for windows phone 10 we can get from this article?

One OPERATING SYSTEM to rule them all
It’s about unity
User interface
Computer keyboard and messaging
Camera in addition to photos
Project Spartan.

There is already a post of this https://forum.lowyat.net/topic/3477402

Please use that instead =)