New Oreleans currently has less than 1/2 its original population (currently close to 200,000). For the Hornets to go back there, the NBA would have to fund them or something because there is no way they are drawing 20,000 to a game. It would be like 5,000-8,000.
Seattle's new owners will play hardball to get new stadium with a threat to move. If they don't get it they'll move to NOK.
The league will take over the Hornets (much like MLB did with the Expos and baseball) and find the right city and sell to owners:
Some possible choices:
Puerto Rico (David Stern would love this)
Mexico City (David Stern would love this too)
Las Vegas (All-Star game is there this year, steps are in place)
San Diego (top 10 city in population, NBA is missing)
Link to populations of U.S. cities: http://www.infoplease.com/ipa/A0763098.html