In case you've missed today's news, Horizon 3 was announced at E3. Here's the launch trailer:
There's lots more info available over on FM.net as well, starting with the official announcement. There's three different versions available to pre-order, and you can get a bonus car depending on which retailer you order from (see the info page for details). As in Forza 6 there's some loyalty rewards in the form of cars depending on your Forza tier, whether you played FH2 or FM6, and if you've been a VIP in either FH2 or FM6.
FH2 was the reason I bought my xbone, I enjoyed it a huge lot and am looking forward to the end of September for some fun roaming around Australia. Time to make cars fly again!