The next generation of Windows: Windows 10

Bought the Windows Phone 8.1 Lumia Denim (build date September 2014), back in mid-November...then, received the new coming update (build date Dec 15, 2014) including Cortana, Microsoft’s personal digital assistant some days ago.
I'm quite impress by this Phone OS...its even more fluid now. I think i"ll let the phone to receive Windows Phone 10 update free and i'm really looking for to wait the O.S to surface for PC, not to upgrade that last one though!:)

Edit:
Looks the Windows Phone 10 might at least include a rollback feature SOURCE

This sounds a lot like the printer business model. Give it away (practically) knowing that the user will have buy something to make it work (ink). In the Microsoft case, the OS is free but it looks like all new releases of software will be required to do any real work--AKA; the App Store. And I don't particularly like the idea of it creating folders for me. I do my own photo organizing.

Has anyone tried to run older versions of Office? Or will Office365 be required?

So far, I don't see anything for me. I don't have Xbox, tablet or phone to sync. Everything I need is right here.

I loaded office 2007 and it worded very well,
GIMP 2.8.10 as well didn't bother with CorelDraw x6 though but I'm sure it would work

Build 9926 clean install did not create the system reserved partition when all other builds did with a clean install of them,
I rolled back and clean installed 9879 build and used the update system to get the build 9926,
That did not go well at all
Locked the hdd I was testing it with,
Now tonight I get to see if Linux can slavage/ clean the drive,
Clean install has never failed to work but the update system seems flawed in my resent case
Not really solved yet,
Solved 250mg recovery partition ? - Windows 10 Forums

As a non-business user, I'm planning to stay with WIN7 until the current tower dies or the OS becomes unusable for some reason. I went from XP to WIN7 with no ill effects on our usage. So, I'm comfortable avoiding the WIN10 experience. I think I'll let MS work out the new revenue model and what ever else comes with it. I'm no longer a techno geek, so have fun folks.

Windows 10 is still in tech preview so it's too early to tell. WMC, as I understand, is not in that release but nothing is carved in stone. The same goes for hardware and software compatibility. Most are using Windows 8.1 drivers. I would certainly wait for an official RTM version and a compatibility check before upgrading. I was hoping for a compatibility utility like Microsoft had for XP to Windows 7. There was a lot of hardware that couldn't make the trip and the primary reason I built a new machine. I'm not ready to do that again. :)

Most issues I've found is with the intel quick fire technology and win-10tp using it,
My mother board is not compatible with it old intel mobo but 10tp tries to use it anyway
The end result is a fast asleep hdd which will not wakeup mother board can not sent the wake command

Microsoft needs a very good tool for compatibility for this new fast startup stuff for sure.