Details should be announced this week. MIA will be announcing that, over the next five years, they will be laying off 20% of their staff. With the lay-offs, MIA hopes to be able to reduce what are some of the country's highest landing fees, in order to better compete with FLL. They will also be stepping up efforts to lure Southwest and jetBlue, two airlines they have been wanting for a very, very long time (while I think luring Southwest is unlikely, given Southwest's recent choice of airports, like PHL, SFO, IAD, and DEN, I would not say it is impossible as I would have a few years ago). Contrary to popular belief, MIA is not congested, and has plenty of gate space for new carriers.
So far this year, MIA has had it's best traffic year since 9/11, and last year was the fastest growing major airport in Florida (growing at a faster rate than MCO and FLL). If growth rates continue, 2008 will be the busiest year in MIA's history. None the less, costs are still very high, and MIA is actually over-staffed as is, so the job cuts will hopefully go along way towards helping MIA curb or reduce rising costs for airlines operating to the airport. One reason for MIA's high costs is that they are a "pay per use" airport with common gates. Airlines don't lease gates, they pay for the use of them for every flight. This has it's advantages, and for international carriers with only one or two daily flights, it can actually save them money. However, for airlines with more than just a small number of flights, it gets very expensive.