Now this is probably right off, but didn't the story say that if the Dragon King drank the blood of the young dragon, he would be immortal. So if the Dragon King is in Reptile's body it would probably be safe to say that the Dragon King is either immortal (which would mean some kind of artifact or weapon that could kill immortals, even Raiden and Fujin, would probably come into play), he is being controlled (Shao Kahn anyone?) or someone is protecting the last dragon (Maybe Kung Lao fought the DK while Bo' Rai Cho ran off to protect the dragon?). So looking at this reasonably, if Reptile is the Dragon King, we are likely to be here.
Scenario 1) Dragon King is immortal, maybe killing Kung Lao, Sonya, Jax and maybe a lot of Earth's best fighters. Which might mean that a character able to take immortlity (Nightwolf?) or a weapon that can kill immortals (I'm thinking Dairou has this, or maybe Sub-Zero's Dragon Medallion, or even Quan Chi's Amulet). This probably means:
S1A) Bo' Rai Cho is training a warrior to keep Earth safe for a while.
S1B) Establishes the importance of Quan Chi and his ammulet. If Scorpion gets his petty revenge, the Amulet may be lost forever, which Earth's forces can't allow, meaning it's Scorpion vs. Earthrealm vs. Dragon King's forces.
S1C) It explains the shortage of Earth's warriors, as well as Liu Kang's returning and Konquest.
S1D) Maybe it could explain the return of Smoke? Sub-Zero's going on a dangerous mission, so Smoke joins the operation.
S1E) Earth's Special Forces could be either a) dead or b) Preparing a nuclear weapon. Cyrax could be kidnapped by Nitara, so Kenshi (who has the least knowledge of military weapons) goes on a solo mission looking for him, only to run into Ermac, or something.
S1F) Kitana could easily be killed by the Dragon King, so Sindel wakes up and attacks, while Tanya sees this as an oppourtunity to take Edenia.
S2) The Dragon King is preparing to attack Earthrealm head on, as Bo' Rai Cho has the Dragon. Earth's Special Forces might be behind the battle lines as a back-up, while Kenshi goes in. Bo' Rai Cho might be training an apprentice that could kill the Dragon King. Liu Kang returns in this hour of need, while Kung Lao might have died trying to hold off the DK. Ben enters as Earth needs all its possible fighters. Same with Kabal and Nightwolf.
