"Somebody paid a lot of money to make sure that title was exclusive."
That line makes me believe they are milking as much as possible out of the buyers. Even though it took seven months for GTA4 PC Version to come out. I feel this one may take longer. If not I would probably say December 2013 / January 2014 for actual possible orders. If the time line is the same as GTA4. But I still feel they are hoping people will buy multiple version for the different platforms they play on.
If you wish to read the article then click this (Link)