First off, I want to say that I love the Halo franchise and want it to succeed, along with all of you.
Now, at the current time, their are three Halo games in discussion, the first is Halo 5. I, personally, would like to see it come out in 2015, in order to give 343 a full three years to work on it, just like how all of the other games always had a three year gap in between releases. 2015 should be plenty of time to ensure the game has all the crucial elements it needs, and is bug and glitch free. They definitely need to improve from Halo 4 (I loved H4, but they can certainly improve). Also, if necessary I would be fine with a possible 2016 release (very unlikely) just to give 343 more time with the new gen Xbox One, although I do not think that this would be needed at all (just saying that I would be fine with that in order to make a greater game). Whatever the cost, I do not want to see the beloved Halo series have a rushed game and suffer from that. I know that in other Halo forums most fans also believe that Halo 5 should be pushed back to 2015 for optimum quality too!
Now, let’s say that Halo 5 does get released in 2015, that means that 2014 is open for one or two “smaller” Halo games, meaning the possibilities of a Halo 2 Anniversary and/or Halo Wars 2. I think that 343 should really make a Halo 2 Anniversary for 2014 like they did for Halo: CE in 2011, being that 2014 is the 10 year anniversary of Halo 2. They have already said that in regards to an anniversary game, they are more concerned with the game and not digits (profits) from it, which is great to hear. However it does sound like they may make it but just not for 2014 which, to me, sort of kills its importance, but it would still be much better to have later rather than never. This, I think, is the best course of action that 343/Microsoft should take.
Also, there has been some serious speculation that a sequel to Halo Wars could be in progress as well. This too would be a really great addition to the franchise. Halo Wars was, in my opinion, a great game and a sequel to it would be very successful, when it comes to RTS games, as well.
It could be possible for both H2A and HW2 to come out 2014, but I think that the best option would be to just release one of those and then in 2016 the other one could be released. It might also be a bad idea to have both of those come out in the same year because with those two Halo 5 and Halo: Spartan Assault, that would mean that four Halo games would be released in about two years, and that would probably just be too many in too short of time.
To summarize, the most straightforward path I think should be taken is in 2014 release the Halo 2 Anniversary. Then in 2015, after three years of production, Halo 5 should be released. And finally in 2016, Halo Wars 2 is released.
Again, this is just my opinion on what should take place in the next couple of years in regards to the Halo franchise. I’d like to see what everyone else thinks too so please leave your opinions on this topic too!