On Connect  http://connect.microsoft.com

Its called a PCTP  but its based upon the Release Candidate.

A refresh of the trial download for theWindows Embedded Compact 7 Public Community Technology Preview is now available to you. The download is based on our Release Candidate (RC)and is subject to the Prerelease EULA terms.

Please ensure to uninstall any previous versions before installing this drop.

 Windows Embedded Compact

I downloaded my coping overnight.  Its about 8Gig