From someone who's followed many beta and pre-beta game forums I can say Destiny isn't really building up all that much expectation. Your average game has unrealistic, technologically unfeasible expectations that would never get in but are thrown around like fact and demanded it should have it. For the most part the threads here are talking about things that Destiny is confirmed to have like space combat, competitive PVP and what not. It might not be amazing right off the bat but they've already made a 10+ year commitment to the game so I fully expect any issues or lacking features to be fixed or added. This isn't some small time company's first game, nor is it a completely new genre for them.