During today's panel at Comic Con, Aaron Forsythe answered a question from the crowd concerning the Modern format played at this year's Community Cup. The audience member asked what the future for the format held and Forsythe said that Wizards of the Coast would be 'moving forward with the Modern format.'
This is taken to mean that we will see Modern as an officially endorsed format by Wizards and will bring an end to the battle of Overextended vs Modern.
Assuming no changes are made to the structure of the format, aside from possible changes to the banned list, Modern will be constructed of all cards from the first Mirrodin block forward. This is when the card frames changed to their current form and acts as an easy marker for new players to discern whether a card is legal or not.