Halo has held a special place in my heart ever since middle school. My friend would bring Halo 2 over to my house and we would just play it all night, 1v1ing on the biggest maps (lol) and repeatedly blasting through the game on Legendary co-op. That is something that no other series is going to do for me, even aside from the level of quality in the games, the memories are there. Since then, Halo has evolved for me into a form of creative expression through map design and even a source of income through making youtube videos. I fully expect Destiny to be awesome, but nothing is going to pull me away from Halo for too long as Halo is the main reason why I even play video games at this point. It's disappointing when the game's new developers make stupid mistakes, but their stewardship of the franchise has honestly gone better than I expected so far, and I look forward to seeing them learn from their mistakes and Bungie's successes.
In short, yes I will be playing Destiny. That's not going to make me stop playing Halo, though.