Destiny is very similar to Halo. It is a MP gameplay is very different than COD (Mainly because of the shield).
Right now there are a lot of PlayStation users who do not know Halo at all and are like "OMG this game is so awesome, so innovative MP gameplay" while for Halo players, it looks like another Halo MP (do not get me wrong, I'm looking forward for the game, mainly because I'm a Halo fan).
COD > Halo in sales because it is easier to play COD and get some rewarding kills than Halo/Destiny (based on the Alpha).
Right now people (esp. the ones that are "discovering" this type of gameplay) are super excited and believe this game is going to be the next COD... But in a year from now I expect COD to come back as the leader in all FPS on console while Halo/Destiny will still be very good but will not have as much success in MP.












