I wouldn't mind seeing an invasion or an RPG invasion mod done privately, but I really don't want Epic to spend their time on it. I'd like to see this game sell, and honestly I don't see invasion as a selling point. They'd be better off to really polish the core gametypes and maps as much as possible, because the initial reviews of a game have a big impact on sales. Then if it really becomes popular, they can always add stuff like invasion in later like they did in 2k3.