Back 7-8 years ago when I was in college, ImageReady was used mostly for splicing images, adding HTML actions to images etc, I suppose that functionality has been added into photoshop now?
Hmmm.... not sure, I haven't dabled in most of that recently. I did notice that CS3 doesn't come with ImageReady that I could see, and the Browser/Adobe Bridge changed yet again. Most of what I deal with today is mainly in Illustrator. I kept more up to date when I was still working in Photography. Now I work mostly in the sign industry/vehicle graphics, so illustrator has taken most of my time in the day. I suppose I should keep up to date.
Added:
Two versions of Photoshop CS3 seem to be available: (CS3 and CS3 Extended)
http://www.adobe.com/products/photoshop/compare/
Hmmm.... I don't see much explaining anything about ImageReady, so it's either toasted and incorporated into CS3, or they threw it into InDesign.