Microsoft is expanding the Windows Insider program to students and teachers who are using the Windows 10 Education SKU in their schools and colleges. People who use that version of the OS can now go to "Settings", then "Update & security", and then "Advanced options" to opt-in to getting Insider preview builds.
Microsoft's Gabriel Aul stated:
"By joining the Windows Insider Program and running Windows 10 Education – you can help to shape the future of Windows for education customers. You can be a part of the ongoing process of improving the features and functionality of Windows that has helped us build the best Windows yet. Windows 10 Education is available through Microsoft Volume Licensing. Individual students in schools participating in the DreamSpark program or eligible for the Windows student use benefit may also be able to download Windows 10 Education as a benefit of their school's partnership with Microsoft."
Microsoft just released preview build 14257 of Windows 10 for PC to members of the Insider program on the Fast ring.