macdave - 1:43 am on Mar 1, 2006 (gmt 0) [support.microsoft.com ] [msdn.microsoft.com ]
I got the same email from DoubleClick, and my first thought was "didn't this happen two years ago?" Apparently not. A couple related documents on the Microsoft site have been updated quite recently:
Last Review: February 28, 2006
...Microsoft is releasing a software update to Microsoft Internet Explorer 6 for Microsoft Windows XP Service Pack 2 and for Microsoft Windows Server 2003 Service Pack 1. This update changes the way in which Internet Explorer handles some Web pages that use ActiveX controls.
Updated December 2, 2005
After a forthcoming update, Microsoft Internet Explorer users will not be able to directly interact with Microsoft ActiveX controls...