Does the early 2014 MacBook Air use Thunderbolt 1 or Thunderbolt 2? I am considering purchasing a new MacBook Air (early 2014 edition). I'd like to drive two external monitors from the laptop.

Based on my reading the 2013 Air only supported Thunderbolt 1 and therefore DisplayPort 1.1. With the semi-model-refresh that occurred in early 2014 was the Thunderbolt controller updated to version 2 and therefore DisplayPort 1.2?
No, The Early 2014 MacBook Air has Thunderbolt 1 and therefore DisplayPort 1.1.

Source : Apple Support Page