Pokemon Go seems to be expanding to include Ditto in addition to 100 Gen 2 Pokemon. The news was first spotted by The Silph Road who found the data within the latest Android update. Here's the quick version of what they saw...

• Ditto is being added to the game. It looks like his move is "struggle" if he's going against another Ditto, and that his "transform" ability automatically takes effect against another Pokemon. Transform was added as a move to the game.
• 100 Gen 2 Pokemon (Chikorita, Totodile, Cyndaquil...etc) are being added to the game. No move set data has been added to any of these Pokemon so no idea when they're being added. Lugia And Ho-Oh are confirmed. 
• Daily Quests will be a new thing you can complete for rewards. 

If you are someone who has stuck with the game in it's lower play period looks like you're going to have a leg up when people inevitably flood back to the game! I'm excited for Gen 2! I would be more excited if Niantic would let us add locations again so I could get some Pokeballs from my home before heading out!