God, this makes me think of when we read 'The Giver' in 8th grade! (one of my reading teacher's favorite books to read)
I think that if a utopia were possible, it would happen. For a while. There would be a lot of manipulation of peoples minds and ideas, but I think eventually the whole thing would cave in on itself.
If I were to make a utopia, it would probably benefit EVERYONE. Um... *pulls out folder from 8th grade* It would be on a remote tropical island, probably somewhere in the pacific. Um... computerized teaching (no changes to the arithmetic this way), a bunch of DNA editing (make everyone color blind; when you know a color, you can say you like that color, and that is an opinion. also, make everyone look... at least similar), a heck of a lot of killy-killy (anyone, and I mean ANYONE, with a severe mental disability [autism, retardation, bipolar, etc.] would be killed.), and... I don't know what else.
But, as I said before, one small mistake could lead to the collapsing of the utopia I've created.