Actually we know a fair amount of Cataclysm and FFXIV. The Old Republic is the only one that we still no precious little of. The only thing we really haven't seen with FFXIV is the world and zone design. SE has already given quite a few detailed explanations of the class system, races, mobs, Guildleves, and some weapon and armor information.
Are you stupid? We don't know ANYTHING about FFXIV. Detailed explanations? What detailed explanations?