Of course the camera has already done things to the raw depending on the setting in the camera but I consider the scanner the equivalent of in camera RAW.
I don't think scanners are equivalent to a raw converter. Raw images are more like latent images than negatives, and they've already been digitized. (None of the camera settings other than image format affect the raw data for almost all modern cameras by the way) Negatives have already had some processing by the developer, and the scanner itself can introduce quality problems during the digitization that you wouldn't see in a digital camera file.
A while back when I was at Applied Science Fiction, I worked on technology for both scanners and digital cameras, and there is a big difference in the characteristics of the files. One example - with digital images from scans, you can do a much better job of correcting grain by analyzing the characteristics of the grain in the different color channels and you can't do that with a digital camera image. If you're working your scans and digital camera images through exactly the same processing, one of them is going to not look so great.
If you're just using the vanilla TWAIN driver to get your scan into CS3, you might try taking a look at something like
VueScan - it's like Adobe Camera Raw for scanners and will write out DNG files which can give you more flexibility in Adobe's software.
-Colleen