"Strategic" Campaigns, akin to Total War are more likely than "narrative" campaigns (like seen in Age of Mythology) simply because of the vast amount of work necessary to achieve a good result for a narrative campaign (storyline, writing, scripting, voice acting, etc.). Could have "mini" Strategic Campaigns (Peloponnesian War, Punic Wars, etc.) and a "Grand" Campaign, like you said. And also different victory conditions as you mention. The different victory conditions would allow us to add historical flavor while still not having to go through all the work of making proper narrative campaigns. In the end, we could always give folks the ability to make their own narrative campaigns, and we probably will.