I believe that each booster will contain a full art land. As for lands only dropped in packs we do know that the fat pack will contain a pack of full art lands in it as well + the ones you get from the booster packs.
Also, the full art fetches, shocks, and other assorted goodies will take up a foil slot within the packs. Not sure if this will exclude the possibility of also receiving a full art land. But who cares if you got a full art shock in a pack $$ value has been made.
Hope I helped somewhat