Here's the info on it from the Embarcadero web site:
Get the Next Major Release Free!
Buy XE7 and get a free next major release to keep you up to date with latest hotfixes, exclusive content, support and more. Purchase a qualifying RAD Studio, Delphi or C++Builder XE7 product by March 31, 2015 to get the next major release free!
Availability: Available on purchases from February 23 - March 31, 2015.
How to get it: Once the next major release is ready, you will receive email instructions on accessing the maintenance portal to redeem your free copy. You must redeem your free copy within 2 weeks of the release.
Restrictions Apply. Not available with purchase Academic and Starter editions. See qualifying SKUs.