Bungie describes Destiny as a modern MMO and FPS hybrid which it says should be thought of as a "Shared World Shooter," one that's set in a persistent, always-connected world with cooperative play and a sandbox approach the most important core elements.
There was no mention of PS4 or Xbox 720 in Bungie's big reveal last night. Only PS3 and Xbox 360 have been outed so far as the machines you'll be able to play it on, with the developer even disrespecting PC gamers by claiming there won't be a PC version as no one's bothered by the old mouse/keyboard play mechanic any more.
In fact, the entire Destiny launch announcement seems to have been one big attempt to kickstart the game's pre-ordering campaign, which means, if you're happy to base your buying decisions on five seconds of footage and the developer's reputation, you can order the game right now ahead of its December 31st launch date. [Bungie]