According to a source who spoke to Gamesbeat, Blizzard has now delayed the release of the Diablo 3 expansion until 2014.
A release date for the expansion for their hugely popular ARPG has never been announced so we have to assume that based on the comments they had originally planned to release an expansion this year at some point. With the console version coming at the beginning of September, it would be tight for them to push out a PC expansion for later this year. However, when pressed for an official comment on this date “delay” Blizzard declined a response.
The fact that the PC version of the original game still needs work to bring it up to the Diablo standard, and the slow pace that Blizzard are patching the game, we never thought an expansion would see the light of day in 2013 so the information from the “source”, if correct, is not surprising in the least.
Blizzard also recently scaled back their development team working on their unannounced MMO called project Titan when they decided to go back to the drawing board with the game’s design. Staff will have been shuffled around the various Blizzard titles which will have some impact on development times.
So in essence, as we never had an official release date, the expansion can’t really be considered to be delayed.