Previewed at WWDC, launching in the fall.
Apple Updates Boot Camp With Windows 10 Support
Boot Camp 6 also includes support for several Mac features within Windows 10, including USB 3, USB-C, Thunderbolt, built-in SD and SDXC card slots, built-in or external Apple SuperDrives, and the Apple keyboard, mouse and trackpad.
Windows 10 support is only available on select Macs with OS X Yosemite and the latest version of Boot Camp, which will automatically download the support software (drivers) needed to use Windows 10 on a Mac.
Boot Camp requires an authentic copy of Windows 10 for a new installation, which can be purchased from Microsoft in an ISO file or USB stick for $119. Windows 7, 8 and 8.1 users can upgrade to Windows 10 for free from within their Windows partition as long as the user's software is completely up to date.