The surprise boost comes from a profit-sharing section in the development agreement between the city and the arena’s operator, Anschutz Entertainment Group.
It specifies once that AEG turns a 16 percent profit at the building, the city gets half of any additional proceeds."
If you are interested in how Louisville is doing economically then check out Bureau Of Economic Analysis website they have some very interesting stats. If you don't feel like combing through all of the charts and then analyzing the data then read this post from the Urbanophile. He does a pretty good job for you.
Last but not least. Here is a list of all US rail transit projects from 2000-2009. I wonder what city we all know and love is missing from this list?