Here is a small demonstration of OTA programming of the Atmega128 on the winkel board using avrdude. Also possible with the arduino IDE. I have powered it ON using a power bank. Uploading a simple blink example. No wires!!!
OTA Programming of ATmega128 on the Winkel Board
Over The Air Wireless programming using avrdude tool that comes bundled with Winkel Board. The video is a short demonstration of wireless programming of atmega128 on the winkel board using avrdude command line. HC-05 on the winkel board is paired to my laptop over COM10 (in linux it will usually be /dev/rfcomm0)
A good discussion is also going on here at Reddit