The Layer 3 migration:

Today, almost every connection is turning into ethernet. That said, I have replaced 80% of my routers with layer 3 switches to accommodate gigabit connections. Installing Gigabit after gigabit card in a router is not worth it unless you have special routing/security needs. The Cisco 3750 series has it all when it comes to routing on an ethernet LAN. The stackable feature allows for a fast inexpensive backplane.