Microsoft confirmed today that they too will allow their users to download early in order to play the game right at release from the comfort of their own home.
"We’re thrilled to make Destiny available for pre-order and pre-download for Xbox One owners around the world. This option was available for a short period of time before the official pre-order window opened. We’ll have more details to share soon about the pre-order and pre-download window for Destiny."
As noted, additional details on when the preloads for both consoles will be coming shortly. Destiny launches September 9 for the PS4, PS3, 360, and XB1.
The idea is that if you can preload the game from a digital preorder you don't have people hammering the content servers right at midnight and bringing the entire thing down to its knees. Preloading lets people get the content spread out over a few days ahead of release and when the release time comes it starts working without much fuss.
Those who buy retail simply have the advantage of not having to use their time downloading the content as it's all on the disc... Even though as is the case with the Xbox One and PlayStation 4, all games are installed to the HDD any way, so it's just as if they downloaded it digitally in the end.