With the ADV Pomeg berry glitch, pokemon can be trained while in an egg, obtaining level-up moves and evolving. The fact that pokemon can evolve inside an egg doesn't effect the metagame as even though the fully evolved pokemon is hatched from an egg at level 5, it is not the starting pokemon in the evolution line. However, with this glitch there are a few pokemon who gain some useful moves, that can directly effect the metagame. Porygon, Staryu, and Zigzagoon all get powerful new moves which they can use to a full advantage. Porygon has access to Tri Attack, Recover, and Agility, making it a very powerful set up sweeper, or a bulky pokemon with a 50% recovery move. Porygon cannot have Download while using any of these moves unfortunately. Staryu can now use Hydro Pump, Rapid Spin, and Recover, probably dethroning Squirtle as the best Spinner in Little Cup. Zigzagoon got what it finally wanted with ExtremeSpeed and Belly Drum, however it cannot use that moveset with it's Diamond/Pearl ability, Gluttony. I think all of these are pretty big changes, and you can now use them on the ladder, though if someone is using an illegal moveset (like Gluttony BDES 'Zoon) then tell them it's not allowed and ask them to leave. If they refuse have a moderator or a driver talk to them. Discuss the pokemon and their effects on the metagame here, happy playing!