Sprint has been testing Gingerbread builds for the Samsung Epic 4G for some time now. The latest build to leak is EE03. This build is much better than version ED12 that leaked recently. The GPS, 4G, and charging now work. Also, the temperature sensor appears to be normal.
This is not the final build, but we are a lot closer. It is rooted and ready to be flashed. Hit the source link for instructions.