Diablo III: Reaper of Souls Pre-Download Targeting January
In a recent post to the Diablo III forums, Blizzard Community Manager Stephanie Lylirra Johnson answered questions about the upcoming Reaper of Souls expansion for Diablo III. While the expansion isnt scheduled to launch until March, if all goes as planned, players should see the pre-download for the expansion begin later this month.
The exact date that the predownload will start is still TBD, but we're targeting this month if all goes well, Johnson wrote on the Diablo III forums. Note: this download will begin automatically (meaning, you shouldn't need to do anything special).
Johnson goes on to explain the 2.0.1 pre-expansion patch and the files that it will include from the expansion.
Similar to what we've done with other games, the pre-expansion patch (2.0.1) will contain all of the expansion data that's on the normal disc. So, for players who don't predownload, they'll basically get everything that's available whenever they patch up to 2.0.1.
Caveat: Expansion-only content like the Crusader, Act V, and Adventure Mode won't be playable until March 25th and only players who purchase Reaper of Souls will have access to them.
Source: Diablo III Forums