Basically this means that when the game is released, you won’t have to spend the next hour or two downloading the various patches and data and will be able to jump into the game straight away, assuming Blizzard’s servers will be able to withstand the onslaught. According to the post on Blizzard’s blog, “The download will be around 6GB in size and include things like models, textures, art files, and other upcoming content in patch 2.0.1 and Reaper of Souls that is already complete. By making this data available early, you’ll have leass to download once the pre-expansion patch and expansion are released.”
Naturally you are also expected to have a copy of Diablo 3 installed on your computer already and updated to the latest build for it to work, so be sure to update your game if you haven’t done so already. So, who else is excited for Reaper of Souls?