Prepare to unleash the absolute latest in modern weapons technology against the world's most powerful Generals in Command & Conquer Generals: Zero Hour. In the next era of military strategy and might, you'll need to command a more technologically advanced arsenal to defeat new, more powerful enemies.
Though the vision part is little bit out of date from a 10-year-later perspective, the game itself has excellent concept and most importantly it's very friendly to moders. We don't need something like an SDK which is often difficult to use and has piles of bugs to create our own ZH.
If there's no new RTS game can match ZH's moder-friendliness, perhaps it's reasonable to assume that this game could still be alive for pretty long time, because while there're always people who wanted to be players of the game, there would also always be people who wanted to be the "god" of the game universe.