Thanks for your input. I tried the approval event and when a content editor creates an article it's not immediately published. But the next problem occurs as I cannot find the article back anywhere. There is no message or what so ever.
Hint: remember that you probably have to run the cronjobs script in order to get the node from the original author to the approver, and finally to its published state. This script must either be run manually or by making use of a scheduler mechanism (such as the cron daemon on *NIX systems).