Achievements
Just like in WoW, Achievements will be added to Diablo III and StarCraft II. Achievements such as "Win 100 StarCraft II games", or "Level your character to 100" are the new way of playing online and will be recorded on Account basis. Blizzard have explained that all games' Achievements will give a score that stacks to give you a "Blizzard level". Whether these features will be available only for new games, or all Blizzard's Battle.net games is unknown but it seems likely they will only be available in new releases. A preview of this system can be found in World of WarCraft, where testing is now commencing in the Wrath of the Lich King Beta.

Besides being entertaining, the purpose is also to bring people in to the multiplayer game, as the Achievements will only be available online where they can be checked against cheating. It should be more fun online, even solo. Trading and co-op is just a bonus, and Jay Wilson has even said that Diablo III won't even contain any other networking functionality besides Battle.net.

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Battle.net 2.0 Launch Date
Blizzard never give release dates (...any more! They used to, a long time ago), we do actually have an ETA on both Battle.net 2.0 and StarCraft II. Diablo III's date is unfortunately still held in mystery, but we will probably get a better idea at BlizzCon 2008. We know that the first true peek of Battle.net 2.0 will be given at the latest by the StarCraft II release (more likely by the StarCraft II beta). The StarCraft II beta seems likely to start before the end of the year, so the new Battle.net will at least be available to try out by then. With this information, the definite release date of Battle.net 2.0 then really becomes a discussion of the StarCraft II release date, a few months from now we'll be surfing it and counting the score points to our next "Blizzard Level".