User blog comment:Archivist217/Expansion of Young Justice, if the series renews/@comment-69.47.188.196-20121124191509/@comment-1038387-20121124195228

Actually, the new multiverse (with, so far, Prime Earth, Earth 2 and Earth 23) is different from the old multiverse in which Young Justice was created (with New Earth, Earth-1, Earth-2, Earth-3, Earth-4, Earth-5, etc.)

And I doubt they're doing a crossover. The Young Justice universe is pretty much a self-contained universe; the implications and consequences are too great for a multiverse crossover.