There are a few things that really matter here...
Version Cue 2, if you have it, it will really slow down the operation of the programs in CS2.
Scratch disk placement, it will cause any program to run about half the speed it should if it's scratch disk is set to the same physical drive as the program is install on.
Hard disk speed, 4500 RPM, 5400 RPM, and other older desktop and laptop drives will really suffer here. RAID can really improve load times and write times for anything and is of little cost compared to a new computer.
The Bridge and Image Browser will eat processor time alive, disable these on startup and only have them open when you must.
Other than that, it is a more complicated program to some extent and will take more time to load. Other things can still effect the load time like how many fonts you have installed, how plugins you have loaded, what other processes are running (including items that you can't see like printer drivers, automatic updates, etc...), if you have a virus (or two, five, twenty, etc...). Good luck, I hope this helped!
--
http://usedtoit03.deviantart.com/gallery