1. There's loads of stuff for touch, but it's different stuff
Designed to appeal to experts and novices alike, Microsoft was at pains to point out that it hasn't given up on touch with the new OS. The Charms bar remains for the moment although we expect it to die if you're using a non-touch PC (check out Continum below).
Microsoft says it wants to support touch users who have persevered with Windows 8 and "evolve" the touch UI. (Translated: That means it is changing quite a bit.) The task switching will no longer work on the left. So with that and the charms going, that's goodbye to most of the problem with Windows 8 - and a whole philosophy down the pan.
Microsoft's Joe Belfiore said at the preview: "We want Windows 7 users to feel like they upgraded from a [Toyota] Prius to a Tesla, but they don't need to learn a new way to drive."
2. It's BACK!
As we've covered before, the e most noticeable change is the new Start Menu, which looks somewhat like the old start menu. It brings some features from the Windows 8.1 Start Screen, such as live tiles, and can be resized.
3. Another new Task View (the Windows 8 flippy thing has gone)
Now the Windows 8 task switcher has been unceremoniously dumped, there's a new Task View in Windows 10, too, so users can switch between virtual desktops.That's because Microsoft now recognises that novice users use the taskbar rather than switching in other, cleverer, ways such as Alt+Tab (which also now switches between desktops).
4. Snap Assist helps you snap windows
A new Snap Assist feature also helps users work out which way is best to snap apps to. You can snap windows into new screens and tile Windows - just as you've been able to since Windows 2.0 or maybe 3.0.
5. The Command Prompt enters the 21st Century
Another quite amazing feature for those of us that use it is that the command prompt is now getting keyboard shortcuts! So you will be able to paste in your commands! Hardly groundbreaking, but actually pretty exciting.
6. Improvements to Windows Explorer
A new Home location is the new default view in Windows Explorer. There's also a Share button on the Windows Explorer taskbar (we really hope this is in the context menu, too).
7. Continum - the special one
This is the best new thing we found out today. Continum is an on-the-fly mode for 2 in 1 devices that can automatically change mode if it detects there is suddenly no keyboard attached. So, for example, a back button appears to help you navigate the Desktop with touch if the keyboard is removed. We reckon the charms will also disappear in non-touch mode, although we've heard conflicting news about that.
8. Windows 10 Universal apps
Windows 10 will also usher in a new app model - Universal Windows apps. Windows Universal apps are the new name for Metro apps/Modern apps/Windows Store apps. Take your pick on those old monikers, they've got a new one! Presumably (although we don't know as yet) that these will also work on Windows Phone. Windows 10 will be able to run on all devices from phones to servers and there will be a single app store across the lot.
All older Windows Store apps will work with Windows 10.
9. Modern (sorry, Universal) apps now float on the Desktop
The new Universal apps also work on the desktop and 'float' in their own Windows. Microsoft wants to banish the separation between the Modern UI and the Desktop.
These 'modern' apps on the desktop have a ... icon for more options - replacing the commands that used to be in the charms on the right-hand side of the screen.
10. Windows 10 has lots for Business and Enterprise
Microsoft says it hopes to appeal to business with this release of Windows, more so than Windows 8 ever did. Belfiore said they were "starting the dialogue with businesses today".
To be honest, it needs to - Windows XP is now ancient and unsupported, while precious other businesses want to make the leap away from Windows 7. But part of the reason why Microsoft is demonstrating the OS without all the consumer features is to show enterprises what the OS is capable of at this stage.
This version of Windows will have plenty of other features for enterprise, including a customised store and protection for corporate data. Mobile Device Management will be able to be used for all devices.
Windows 10 will keep personal and corporate data separate.