The DE10 has a lightboard similar to as in other Kato locos, but the usual Digitrax or TCS drop-in decoders won't fit. There's another thread here where someone purchased a special-made drop-in decoder from NGDCC. The cost isn't much more than you'd pay for one here, and it's specifically designed to fit the DE10.
That would be me. The decoder is a good fit, you have to have a little soldering experience though as you need to solder on surface mount LEDs if you want headlights.