InfoWorld ran a story I wrote about the difference between WLAN switches and gateway solutions: It was a rough process pulling this together, but the result is accurate.
The story is designed for IT managers who want to install a wide-scale WLAN but must decide between the different management tools that are available today. While I generally categorized the solutions as gateways, layer 2 switches, and layer 3 switches, each option has its own idiosyncrasies that make it unique. Those subtle differences make it hard to come up with generalizations about which solution best meets any given enterprise need.
I hate to suggest a move that will slow down market adoption, but after writing this story I think if I were an IT manager I'd probably put off the decision as long as I could. There are too many start ups in the market and too many different ways of managing a big network to be able to make a smart choice on a product that is likely to survive for very long.
This sidebar offers some more details about the risk and uncertainty in the WLAN management space.