X-COM has fallen foul of a Take Two re-shuffle which will see it join Borderlands 2 as part of their 2013 fiscal year releases. No reason was given, but considering there’s still Max Payne 3 and The Darkness II due from the publisher in this fiscal year, it just makes financial sense.
The 2103 fiscal year starts on 1 April 2012 and ends 31 March 2013. So that could (theoretically) mean a delay of up to a year.
