Gmail intoduces markers for important emails

Gmail has geared up with improvement in the mail servies. Recently we sawed Aim interoperability in Gmail chat now we see new features which will allow user to put markers on the emails. The New! Marker will allow User to mark an  email  with important and non-important category as per their wish. The two marker '+' and '-' will now appear in the above bar in Gmail which allow user to mark their email based on their importance.
The Gmail will marked the important unread message with a yellow arrow and gray marker indicate important and read emails. Aside of this user can marks and unmarked these with button as mention above. Gmail will also tell you the reason for the marking an email as important, mouse hover on the marker and read the main reason.  But as far as i see  "this conversation contain an important message"  on each of the mail. The important tab also placed in the left panel along with inbox, buzz, labels, Stared etc, which have all important marked emails. This feature is the part of the Priority Inbox and hence can be enable  and disable from there in the Gmail Setting from the priority box setting. It is now helpful for us but still need to have some variation over here with flagging system. Also the Gmail marks the email automatically that is not much effective need to have better algorithm so to have real important email marked so.
Search Operator "is:important".