The Delphi SpeedUp improves the whole Delphi IDE speed by replacing the RTL functions by functions from the FastCode project (http://fastcode.sourceforge.net) and some other faster functions and alogorithms. It also disables the "Source has changed. Do you want to rebuild?" dialog that appears if you have accidentally changed a file while debugging the application.
There is no garantee for BDS 2006 to start faster. Borland already uses optimized algorithms for loading.