EA Released the Beta of the BF2 Mod Tools today [and there was much rejoicing!]

Read about it here: Mod Tools Update

Download them here: Mod Tools Beta

There is a catch though;

Also worth noting is that the current Battlefield 2 Dedicated Server files are not yet compatible with Mods. DICE is already working on a fix for the Dedicated Server files that will be included with the 1.03 patch. In the meantime, this will not prevent Mods from being tested over the Internet entirely. For testing purposes, Mod Teams can still create a non-dedicated server game through the regular in-game multiplayer interface that will allow anyone to connect to your game, either locally or over the net, provided that the rest of the team connects by IP .