The NLL is targeting these markets for future expansion and is in active discussions with groups in at least a few of them:
Boston
Chicago
Houston
Los Angeles
San Francisco
Tampa
Montreal
Ottawa
Winnipeg
Edmonton
All NHL markets except Houston and SF, which are NBA markets. That's where these teams tend to do the best since you literally just have to drain the ice and put down a turf carpet to turn your NHL rink into an NLL field. Same safety nets, same boards, same glass, same size playing surface, same viewing angles.