Right. That's why I don't expect great ideas to be easily or at all incorporated into Bitcoin code.
Changing mining algorithms is not necessary for Bitcoin. The network hashing power is way to big right now for a quick 51% attack. There are other ways to prevent that from happening, so why would we change the mining algo and destroy a large part of our hashing power? I believe that they will implement great idea's, just not new mining algo's.
Imagine a scenario where the biggest 3-4 easily identifiable mining pools/large mining farms are targeted by a large enough power. What happens then? The network is crippled and can't function properly or at all. This would not be possible if there were more than one independent mining algo.
How about the difficulty adjusting not every 10 days but after each block. That's another good idea. Will they implement and accept it? Probably not. If half or more of the hash rate is down for some reason, how long would it take to find blocks with such a slow adjusting difficulty?