The Mobee Magic Charger does away with that nonsense with its inductive charging mini-USB base station and battery pack that slots into Apple's mouse -- no special sleeve or bulky appendage required unlike many after-market inductive charging solutions.
Expansion is limited to a pair of DDR3 SO-DIMM slots (16GB max), one full-size mini PCIe slot that supports mSATA SSD drives and one half-size mini PCIe slot that's perfect for WiFi and Bluetooth.