Reasonable on 12 January 2010
I'd say for PS3/360 titles that are popular and known it's an interesting indicator as I suspect games like MW2 have the highest correlation to pre-order from fans.
Less know IP then less of an indication.
Obviously, with Wii titles it can be hit/miss due to their nature. A fair number of Wii owners probably never pre-order.
Try to be reasonable... its easier than you think...
