Despite the fact that the entire thread is premised on the idea that you don't look at each Pokemon in isolation, and that you have to justify banning and not unbanning, people keep posting as though this were a "which of these single Pokemon should be unbanned?". If you don't get the thread, don't post in it.
		
		
	 
I dislike the premise. Currently, we have an OU metagame where the general public (on Shoddybattle, WiFi, and Smogon) have been playing. OU is a well defined metagame as it is and clearly still has plenty of room for innovation.
The problem with releasing all of them at once is like I said earlier: we won't be playing with OU as we know it anymore.
What we 
need is a non-subjective way to test whether one metagame is better than another. Because there are so many pokemon, we can create very well balanced metagames changing only some 5 to 15 pokemon at a time. Adding just 5 of these "possible Ubers" to OU, or subtracting ~10 members of the 600 Club from OU... both will clearly create a balanced metagame (eventually with testing).
With that in mind, I ask, what do you want by adding these pokemon to Ubers? Not just to Obi, but to everyone. We really need to know _what_ kind of game we are looking for before changing the metagame, else it may just get worse.
Why I think adding powerful pokemon is a bad thing: Everyone loves using UU and NU pokemon in OU, especially if they are well played and possible. In fact, many people openly try to avoid blatantly OU pokemon to come up with unique teams. By adding clearly powerful Pokemon to OU, this is far less possible. The UU metagame, as awesome as it is shaping up to be right now, is not played, nor is it standardized. Right now, GameFAQs, Smogon, Serebii and for the most part ShoddyBattle all agree on practically the same OU metagame. But there is no standard on any site what is and isn't UU.
"Unique teams" cannot compete as well when even more powerful pokemon are added to this mix. Yes, bringing in Manaphy allows strange and wonderful counters like Ludicolo to come out of hiding, but it makes it even a bigger disadvantage for those unique players who want to pull out BL/UU pokemon and still compete in this metagame.
You might just say... then go play in UU. But every other tier however is totally out of whack. OU is the biggest and the most standard metagame, it is a challenge to even find a UU player, let alone a UU player who even follows the same tier system as you.
I advocate small testing, doing it one at a time. We should see if single Pokemon adversely effects the metagame, never releasing them all at once.