Something tells me that Bungie will not release a Public Beta for the first installment of the new IP. Halo 3 and Reach public beta input came from the lens of previous Halos. Since this is a completely new game, our input would have no focus. With the Halo betas, there was a clear goal of testing matchmaking code and mechanics on a large scale. This was feasible because the small, separate, levels of an arena shooter could be placed into a beta build. At the moment we understand that Destiny will resemble an MMOFPS which connotes large playspaces. I believe it would be a difficult task to choose playspaces to test with the public without compromising plot points. Despite this, if there is some arena shooter aspect to the game (Please be a pseudo-Star Wars Wing Game), I hope they'll test this with the public.