If you'd been reading the forums more you'd probably know the answer to that question. The answer is most likely when Marathon comes out because they simply refuse to add more servers and so they are going to have to rip the existing servers out of the Destiny data center and place them into the Marathon data center. Also according to the forums, they refuse to treat their player base with sufficient tender love and care so they are unlikely to agree to print physical discs so that we may continue to enjoy Destiny in the comfort of our homes.