Research in Motion has announced via the BlackBerry Knowledge Base that the official ICQ for BlackBerry IM client is being discontinued as of December 4th.

As of December 4th, 2010, BlackBerry smartphone users will not be able to download or use the ICQ for BlackBerry smartphones application. Users of this application will receive an error message if they attempt to use the application as of this date.

RIM didn’t give a reason as to why they’ve discontinued ICQ for BlackBerry.  Personally, I cannot think of anyone who uses IQC, however, I’ve heard that it is still pretty big internationally.