Lately I noticed a tiny red bug (in dutch we call it a lieveheersbeestje) on a tab in the editor after debugging an application.
It seems that BDS2006 opens units, necessary for debugging, on the fly and implicit closes them when the debug session ends. (This is an editor option) If you stop debugging in such a unit Delphi keeps that unit open. Ain't that great?
I remember debugging a C# project in Visual Studio 2003 where I ended up with an endless list of tabs which is very annoying in my opinion. In VS you have the tabs for design and code besides each other on top of the editor. BDS2006 (and previous versions) have an extra tab at the bottom of the editor for switching between design and code. So in BDS2006 you always have the half amount of tabs in the top tab control compared with VS2003.
So these small features in BDS2006 are great! It gets even better if you popup the context menu on the tab. If you don't want BDS2006 to close the debugged units implicit(an editor option) you can close them by yourself using 'Close all pages opened while debugging' option. Hack you can even close all pages except the one that is active.
Small things, great stuff!