Destiny will enter beta for PS3 and PS4 owners on July 17th. There are some other dates you should keep in mind as well.
On the 21st and 22nd of July, the Destiny beta will be down for maintenance. This is presumably so that Bungie can prep for the July 23rd launch of the Xbox One and Xbox 360 beta.
The fun and games will end at 2:59 AM ET on Monday, July 28th, but not before a Beta Rally on July 26th. The PlayStation blog mentions a special reward for those who take part in the Rally, but was coy on any specifics. One could imagine that a goal for the Beta Rally is to stress test the servers before launch.
Players can gain access to the Destiny beta by simply pre-ordering the game. If you have already pre-ordered and are patiently waiting for the 17th or 23rd, then maybe this trailer can help ease the pain. Bungie hasn’t given any indication yet if they’ll be giving away beta codes in a similar manner to their many alpha giveaways, so it wouldn’t hurt to pre-order just to be extra safe.
Destiny Beta Trailer