TestComplete already has some 'IntelliSense' features: they are Code Completion and Code Templates.
To invoke Code Completion, you should press Ctrl-Space: you will see all the standard TestComplete objects along with their methods and your own routines declared in the test scripts. Please see the 'Code Completion' help topic for details.
The list of the code templates is empty by default but a user can easily add his own templates to it. New templates can be added to this list via the 'Code Templates' dialog. To open it, select the 'Options...' item from the Editor's context menu to open the 'Editor' dialog and then press the ellipsis button to the right of the 'Code Templates' option. Please see the 'Code Templates Dialog' help topic to see the detailed description of how the user templates can be used.
In addition, we plan to improve these features and add new ones in the next major version of the tool. Of course the functionality of the 'IntelliSense'-like features will not be as rich as, for example, in Visual Studio since TestComplete uses scripting languages which don't provide strong typing (they all work only with the OleVariant type).