Just spotted this over at BeBits. There's now available for download a new Realtek Gigabit Ethernet Driver, based on the RLT 8169 chipset family. This driver is a demo which will work for 30mns only, thus allowing the user to test it with their card. If it works and the user wishes to keep it, it'll cost 15 euros to buy it.

This version has been tested with success both on R5 (using the net_server) and on Zeta RC2. As usual, even if you're just testing it and not buying it, don't forget to provide feedback so that the developer can continue to improve it.