How much total is it? And I assume there's no way I can get in on that action?
I find the built-in camera raw editing to be huge. You don't have to shoot pics in RAW mode, it also lets you edit regular pics (jpg) in raw mode. What that means is you get the adjustment tool with sliders to add/remove exposure, color temperature, fill light, blacks, etc.
The selection tool is supposed to be a lot better in CS5, compared to the auto-select (cutout) tool in the older versions.
CS3 also doesn't support 64-bit CPUs, which means it is out of date if you have a newer PC (or will have one soon).