Lost World isn't as world ending as people make it out to be. It's hard to play, and you have to run a deck that is 100% for building just that card, which is a huge risk factor. Even then, you have to be able to manipulate the Lost Zone enough. It's not like you can end the game with the required amount of /general cards alone/ in it, they specifically have to be /Pokemon/ to get the effect of the stadium. Even then, if you play your stadium too early, you could risk having it blown away by another stadium. There are enough variables in there to counter it effectively.
Besides, it'll be refreshing to see Absol and Gengar decks run for Lost World instead of the, now very old, Luxchomp fad.
As for the fact they're putting the /campaign/ versions of the shiny cards into a /set/? I can't honestly express my feelings on that, as someone who fought tooth and claw to get the JP issues of them, without getting very colourful. Shame on you, TPCi. It's not like they're incredibly playable anyway, which is why it doesn't make sense to me to try and cram them into a set.