It turned out Help Line is quite useful. You should not spend a decade using maya to realize that as I did. I really don't know how people learn maya, but I guess few of the users know everything about the software.
Day after day I have the situation when I say: "Whaoo!" And I realize something very very useful feature. I'm going to write about the small discoveries soon.
The Help Line really can help to learn small features in maya. But the standard placement (at the bottom) of that UI part is not best. I realize that when I saw one of my colleague had a different UI setup. Actually he does quite strange things like placing the ChannelBox to the left...but placing the Help Line at the top part before the Shelf is a brilliant idea.
It is really help your eyes to catch the info about the tool, menu item, icon, etc. you are about to use.