Sony (via Twitter) is stating that continued technical difficulties from their last scheduled maintenance is the cause.
In other words: Some intern spilled coffee on their update servers.
Now, I do recall Sony using a similar excuse with "Dungeon Defenders", where they delayed the entire PS Store update (due to issues they were having with another game, I believe it was "Payday: The Heist"), simply so that they didn't have to do 2 separate updates to the PS Store. In order for the game to be released, Trendy Entertainment had to put pressure onto Sony to release it.
I've posted this hint to Deep Silver via Citadel's official forums, so we'll have to wait and see I guess.
Edited by Mystix123, 17 April 2013 - 10:30 AM.