Quote by Vermillion Haze:
Quote by Hektic Juggalo:
That's something I hadn't considered; Microsoft always touted Gamertags as a universal ID across multiple platforms. I highly doubt they would start everyone out at 0 for a new system, as that would be a PR nightmare for them. I wouldn't put it past them to update current Gamer Cards and such with two achievement numbers; possibly a green number representing your GS in 360 games, and a white representing your GS in Next Gen games, or something similar. We will just have to wait and see, but I'm definitely really curious to see the answers to all these questions.
Two sets of achievement scores make the most sense. It's the safest option they have.