This is a question some fans may wish to find out ever since the drop pod was removed from the alpha. Its former purpose was to deploy a certain amount of marines on a spot chosen by a ghost unit. Karune responded basically that the drop pod was redundant, once the medivac dropships were introduced. I recall some fans had compared the drop pod with Command & Conquer, but it was very nice to use the ghost to call them down. Hopefully this can still be done in the World Editor, but that’s unlikely.

Blizzard Quote:
Why was the drop pod removed from Starcraft 2?

Karune: The role of the drop pod fit very closely with what Medivac Dropships already do even better. Overall, through testing, it was far better to build Medivac Dropships to drop off reinforcements or raid, especially since drop pods still needed to be loaded with infantry as well.