Blizzard has done some changes to the infested terran and are currently working hard on balancing the Stimpack ability.
A massive number of minor changes are being made as we are getting closer to the 10th of February. Along with the new infested terran, Blizzard has also worked on the movements of the units, and are working on the balance of the stimpack.
The new infested terran
Links
Twitter.com - Source: Starcraft 2 Twitter