Bungie have revealed that those who purchase a digital copy of Destiny on the PlayStation 3 and Xbox 360 can get a free upgrade.
Up until January 15th, 2015, If you have purchased a copy through the PlayStation Store on the PlayStation 3, you will be able to upgrade to the PlayStation 4 copy at no extra cost.
Vice-versa, you will also be able to do the same to upgrade your Xbox 360 copy to an Xbox One copy. You will not be able to go Xbox 360 > PlayStation 4 for example.
Are you going to upgrade your last-gen version? Let us know your thoughts via the comment section below.