The people at Adobe have been working hard to perk up existing Photoshop functionality, as if all those new CS3 features weren't enough.
Save for Web
The dependable Save for Web feature now has the interesting name of Save for Web & Devices. The Edit in ImageReady button in the bottom corner of the dialog has been replaced with the Device Central button for previewing your image on an emulated device. Other than that there haven't been many changes to the CS2 Save for Web.
So why is there no ImageReady button? ImageReady is gone! It's moved on to software heaven. The more functional ImageReady features such as animation, slices and so on have been absorbed into Photoshop itself while other features, such as image maps, have been dropped.
Personally I always thought it was always a bit awkward when constantly flipping between Photoshop and ImageReady to create things like animated GIFs (which, let's face it, aren't as popular as they used to be anyway).