This has almost certainly been done to emulate a similar move done over the weekend by a certain MMORPG, but here' what we know. The Destiny trial previously locked players to a level cap of 7, but that cap has now been lifted. What this means is that everything in the base game is now free to experience, meaning players can take on the Vault of Glass raid and take part in the Crucible PvP without paying a single penny.
Just to clarify - this does not include The Dark Below and House of Wolves expansions, but at least it means you can decide if you want to give Destiny another go, or if pre-ordering a copy of The Taken King is a good idea. We have no idea if this is the same for the Xbox One version, but if you have any joy be sure to let us know! Thanks to Blade3377 @ HUKD!