According to this MTV story, World of Warcraft designer Jeff Kaplan has said that eventually Blizzard will create an Achievement system in which gamers will be able to track progress across titles like WoW, Diablo III and StarCraft II.
“Eventually, our plans are for the Achievement system to become an account-based system,” he said.
“It’s basically a gamerscore. For now the points are just a ‘WoW character score. As we graduate to that Blizzard Account system, which is right on the horizon, it will switch over to a Blizzard Level.”
He added, “Your WoW score would be just one factor that will go into your Blizzard Level. And rather than call it a ’score,’ we just wanted it to be like you’re leveling up on Blizzard games… You’ll have this Blizzard identity, and you’ll be able to see things like ‘Oh, this guy was great at Diablo III, but he never played Starcraft and he was mediocre in WoW. That sort of thing.”
More through the link.