Yes lets try and build a mall that can compete with the biggest mall in Iowa, and bulid it only 40 minutes away in a town that doesn't have nearly the same consumer base!
I hate to take the position of smart growth here but trying to compete with Jordan Creek is stupid. Yes it would be nice to have some more shopping options in Ames, but you will never have the same draw as Des Moines does. Rather than trying to carve away from their market Ames would benefit more from trying to fill markets not met in Des Moines, find some quirkier shops to give the college town more of a college feel, attract shops not found in Jordan Creek, ect. Don't try to compete head to head with it. Then work on advertising said markets to communities in the area, including Des Moines.
Lets face it, people are going to go to Jordan Creek, you cannot stop that. Insted of trying to stop it find something that will bring people to Ames as well, so that the money flows both ways