DoF is going to be a really awesome game. Those guys are doing a lot of things right and are gonna knock it out of the park. Having said that, although it is an RTS game, in the end the two will be very very different games. DoF will have a lot of MMO and RPG elements that 0 A.D. simply won't have. 0 A.D. will also be more of a traditional hard-core RTS akin to Age of Kings, DoF looks more like something along the lines of Stronghold with some Lord of the Rings-esque RPG and MMO elements. I may be wrong in my analysis, since I haven't been able to get my hands on their testing builds (my rig doesn't meet their minimal specs, sadly). This here is my favorite shot.