The eccosystem of everything connected is what attracts me too. Before xbox 360 I was going the apple route with iPhone, iPod, mac etc but would rather it was tied more heavily into gaming and I think Microsoft might nail it this time (after mucking up with GFWL).I'm looking forward to 10 releasing on the PC and the X1.
the unified Windows "ecosystem" is actually a big attraction to getting an X1.
I really hope the new Edge browser is a big improvement over IE, which has been a frustrating experience on Windows 8 due to constant crashing.
I think the developers only needing to write code once is a huge thing and should lead to a lot better provision on all devices. Windows Phone for eg should start catching up on the apps front.Unlike with previous versions, there will not be a separate Windows Phone 10 operating system. Instead, Windows 10 will be used across all Microsoft devices, including desktops, laptops, tablets, smartphones – as well as the Xbox games console and HoloLens, Microsoft's new wireless holographic headset. Windows 10 could also enable users to manage devices and appliances across their home.
Microsoft revealed at its recent Build developer conference that the release of Windows 10 will be staggered across other devices, meaning that Windows 10 will come to smartphones after the PC launch. There will be a single store to buy software from, with developers only needing to write their applications once for all devices.