Canon’s website posted v2.0.0 fw for the 20D:

http://web.canon.jp/Imaging/eos20d/eos20d_firmware-e.html

Only changes is support for the wifi transmitter, which I don’t have. 🙂
Support for the wireless file transmitter WFT-E1.
Support for the wireless file transmitter WFT-E1 allows high-speed image transfer by connecting EOS 20D and personal computers through wireless/wired LAN.
*This function works for EOS 20D when the WFT-E1 firmware is 2.0.1 or later.