The Wall Street Journal had a good article on Omaha last week. I can't find the article online, but an excerpt is below from the Omaha Chamber site.
One important point they mentioned, and one DM should learn from, is Omaha annexed many towns as it grew. It didn't want to get surrounded by suburbs like KC and St Louis, which has resulted in massive population loss and stagnation for those central cities.
DM is at a point where it needs to continue to expand south and continue to keep those avenues of growth (land) open or it will become landlocked too (as it has to the west).
http://www.omahachamber.org/news/NewsDe ... ryID=12062