I think that depends on how well DA does. If it's a windfall I'd expect to see Information or Modern Age by June at the latest. Considering all they're doing is adding 12-24 hours to upgrade times, giving us busy work to upgrade the refinery by 15,000 oil, upgrading graphics, and adding a description to the new troop upgrades it can't be that hard to do. Maybe it'll take slightly longer if they plan on having four more wonders, only two of which will be remotely useful. But the relatively barren and piecemeal way every age since atomic has been doesn't inspire much confidence.
Congratulations, you hit level 285! So, without the aid of crowns or rush events, you'll be able to get your first Digital Age troops in........51 days! 17 for tc, 17 for factory upgrade, 17 for troop upgrade. Whoops! You'll probably have to spend two weeks upgrading your refinery for a slight upgrade, before you can tackle that factory and those troops! Surely those mk.10 heavy tanks and (insert adjective) rpg's will be worth the two month wait!