Just as HeadlessFrie said, Depending on how Bungie works things our characters could be (1) server side when logging into Destiny with your bungie account, or (2) saved in a game file on the console it self. If it's (1) then it could fairly possible to be a yes, transferring characters from 360 >to> Xbox one, or and PS3 >to> PS4. If it's (2) then no. Both the new gaming systems are good in their own way, I no idea what the PS4 exclusive content is or will be, but my guess is what ever it maybe will only be cosmetic i,e like some kind of dye camouflage for armour or for a gun or something like that.