i dont see shaymin as being even remotely usable in standard play, to be honest. granted its not as simple as him being 'a bad celebi' as so many have made him out to be, but he is not a solid pokemon i dont think. he gets access to a good move... and thats it. granted pure grass has nice resistances, but this thing honestly just doesnt DO anything. heal belling seems a bit less useful this generation, and he has essentially zero type coverage.
celebi is a tough one id say, and i havent played d/p enough to have an opinion one way or the other, so ill ask this question: can you honestly tell me that celebi got a boost in usefulness larger than tyranitar did this generation? celebi was fine last generation, and since EVERYTHING got better, i dont see how celebi became harder to counter or somethign like that. granted there is no more dugtrio, but the fact that pursuit is being used pretty much all the time makes celebi trickier to use. if i had to sway one way, id say it should stay in standard.
manaphy seems kind of scary in some ways. kinda because of the fact that he gets tail glow and owns shit up, kinda because of the fact that grass knot does absolutely nothing to him, but primarily because im scared of his ability. i havent seen any manaphies on wifi, but jesus christ, rain dance/rest/ice beam or something/surf with wet rock looks absolutely retarded. can heal 100% of its health whenever it wants to, and has the defenses to not have to do it every turn. oh, and rain dance makes gyarados funkier and nullifies sandstream? i think people are a little too OMG TAIL GLOW to realize how potential crazy this thing could actually be.