It's been awhile since we have had a legitimate threat from an NFL franchise to move to another city, and we still don't have one. However, if things do not change soon for the St. Louis Rams the folks in Los Angeles might want to dust off those stadium plans.
The Rams were smart when they signed their contract to with the St. Louis Convention & Visitors Commission. In 2005 and in 2015 the CVC had to make whatever improvements were necessary to make the stadium a "first tier" stadium (meaning it had to rate within the top eight in the league).
With the due date coming up the Rams submitted a proposal for $700 million in renovations--and were denied.
To be fair, that is a lot of money and the CVC has said that they simply don't have it. However, stadiums are becoming bigger and better every day. If they don't keep up with the Jones's they might find themselves watching the moving vans as they drive out of town.
Because someone will spend the money (that's your cue LA).
There is still time to work things out. The current contract runs through the 2014 season. After that they could go yearly or move.
So if there is an enterprising city out there that wants to have an up and coming NFL team in town get to work on your proposal, because there might be one looking for a new home in a couple years.