The gamemode was hinted at first on the issue #251 of Computer Gaming World.
"According to the Epic team, the biggest addition to the next Unreal Tournament is a game mode currently code-named Conquest, in which two teams battle to take control of one another's bases. Considered Onslaught mode's successor but bigger, Conquest will take advantage of the Unreal Engine 3's ability to seamlessly stream maps by putting you in a battlefield the size of several maps stitched together. Players will battle on one of two teams, each of which holds a certain amount of territory at any given time - and each side's territory will actually look physically different, so as you take territory, it'll convert from, perhaps, the Necris' neogothic towers (check out the kick-ass concept art for this on the background) to another team's more lush surroundings. As in Onslaught, you0ll vie for strategic objectives scattered around the maps - take out a bridge to cut off a supply route or capture a bunker to occupy the territory surrounding it, for example - but while you'll be able to make forays into the other team's territory, a limitation on how long you can be there without losing health will keep combat focused on the front lines. Conquest will also include a resource-management aspect: Certain bunkers will house Tarydium resources that determine how quickly your team can build assets such as vehicles and turrets. But controlling the lion's share of the Tarydium doesn't automatically secure your team victory. The number of bunkers you control directly opposes the speed at which your resources regenerate, so the more bunkers you control, the slower your resources appear. It's a good way to ensure that a successful push on one team's part doesn't essentially end the game. Conquest should look more like a progressive game than the limited-time deathmatches and CTF games populating many current Unreal servers. There may be the option to treat a conquest match like a long-term war, so you can play, take a break, and then go back and play more later. This should allow for improved strategic opportunities. If things turn out how Epic described them to us (the mode exists only on paper right now), Conquest should appeal to a wider gaming audience and provide a place where longer-term strategy, teamwork, and face-to-face fragging all meet."
During an interview with BeyondUnreal, Steven Polge also gave more hints about the gamemode:
"Conquest is Onslaught meets Assault, with the addition of optional missions. Basically, the idea is that there is a larger scale campaign with a battlefield situation back and forth. [Steve stops and blows up a Manta] And along the way you will have these optional missions that you can choose to do or not to do, but that can effect the outcome. For example, if you take out the command center then it will affect their ability to send stuff or maybe even take out an enemy bridge that keeps them from bringing their big weapons over. With the advantage of our seamless streaming technology the campaigns will be a much larger scale than Onslaught. Rather than having a single mission or objective it will feel like a campaign where the battlefield will move back and forth across multiple levels completely seamlessly. One of the things we think that make Unreal Tournament what it is is that you have very intense situations and you are never out of combat for very long. The actual battlefield or frontline where you'll be fighting at any time will be a relatively small area where everybody is focused and fighting together. [Steve then moves through the level, mowing down opponents (and missing a few ;-) and sets the explosives.]"