In the leaked Windows 10 Build 10036, you can notice that Microsoft has updated the design of some controls in universal apps. For example, take a look at the slider and toggle button controls in the above. Those are new designs that will be coming as part of Windows 10. The new controls have more curvy design than the purely digital Metro design controls.
Take a look the old style below,
Which one you do you prefer? New one or the old one?
Image Credit: TNSC