Hard to tell, I expect alot of the sales will be digital with this one as it's been available to pre-order + it's really cheap on the PSN store.
But VGchartz sales only:
NA: 38k
EU: 50k
http://gamrconnect.vgchartz.com/thread.php?id=130023&page=1# Official Playstation Vita Thread! Come in and join!!!