Being from the region, I can only predict that PBI could very easily and most probably will be a future FLL. To the surprise (and delight) of all concerned with aviation in Broward county over the last 10 years, FLL has turned itself from a small "spoke" off major hubbs to becoming a large "focus city" of sorts for numerous airlines. It is in the process of a large construction campaign adding a new Terminal One, and retrofitiing Termianals, 2,3, and 4. Several low cost carriers have had fabulous sucess at FLL, Airtran, Midway, Spirit, Delta Express, Metrojet, and Southwest all have strong proiftable operations. New entrant carrier jetBlue has obly been flying for several months, and while it is too early to tell if it has also been a proft center, the airline claims to have gotten better than 70% loads. The only looser in the field was TowerAir who disontinued its FLL-JFK run after filing for bankruptcy in Chapter 11 proceedings.
West Palm Beach, FL has been growing at a similar allbeit more restrained pace than its southern neighbor, but a need for resonable low cost jet service still remains. While a smaller airport than FLL, PBI has room to expand and most definately will be forced to soon. While Palm Beach County has the reputaion for being a playground of the rich and famous (Boca Raton, Palm Beach, Manalapan, and Palm Bach Gardens add to the panache) their is a very visible middle class element just as their is in Broward County. Aircraft noise and traffic congestion has not been a major issue at PBI which will not inhibit growth. Look for the next 5-8 years to see trememndous growth at PBI a la FLL. Airtran, Midway, and JetBlue I predict will start or restart operations there. Southwest may wait for unusally high landing fees to drop somewhat.