Square Enix has revealed that it cut 12% of its overall work force between 2009 and 2010 in its 09/10 fiscal year report.
Square Enix had 3805 employees at the end of March 2009, including the employees of Eidos who Square Enix would acquire the following month. By March 2010 the Square Enix group which includes what was once Squaresoft, Enix, Taito and Eidos had a headcount of 3338.
As mentioned above, that's a decrease of 467 staff, or 12%. The cuts came from across the board - studios were slimmed down in Japan as development of Final Fantasy XIII came to a close whilst Eidos studio IO Interactive suffered cuts.