The Armored Warfare lads have posted an article showing in more detail on how the Support Shells for Artillery will work, there is a lot of details so I will post the link to make sure you wont miss anything: http://aw.my.com/us/news/general/feature-preview-new-artillery-shells
They actually nailed right my only concern that could make this be a failure, the artillery will be rewarded for supporting random players:
"When using smoke rounds, artillery players are rewarded for breaking enemy line of sight to their allies."
"When using illumination rounds, artillery players are rewarded for
spotting enemies as well as any damage dealt to targets that are
Cant wait to test this out on the 13th August. :)