What about animations, image maps and other advanced Web graphic techniques? Photoshop itself can't do these tricks, but can do so by jumping to a companion application called ImageReady (included as part of the Photoshop package).
Adobe claims that Photoshop now supports automatic slicing of images and generation of the HTML to build the image on screen, but actually doing this is a bit more complex than it sounds. You can't just slice an image in Photoshop, you have select Jump to ImageReady (which starts off ImageReady as a separate program) from the File menu, wait for the program to start up and load the image, and then do the slicing in ImageReady. If you then want to pass the result back to Photoshop, you have to select Jump to Photoshop from the ImageReady file menu.
At least you don't have to save and load the images. Selecting the Jump to option automatically passes a copy of the currently selected file to the other program whether it's been saved or not. But it's a rather inelegant solution that takes up a lot of memory because you are running two image editing programs instead of one. With several reasonable sized images being passed between the two programs, even my 196Mb machine started to complain. Of course, this could be avoided by planning the workflow of images to avoid having to run both PhotoShop and ImageReady at once, but it's still irritating to have two similar programs hogging valuable memory.
It's the same sort of process for creating animated GIFs. Photoshop still doesn't directly support them. If you try to load an animated GIF into Photoshop, all you get is the last frame. To create animated GIFs, you have to create the animation as a series of layers and then pass this layered image to ImageReady for animation, or create the whole thing in ImageReady. And although ImageReady isn't a bad program, it ain't Photoshop. I mean, it has lots of nice features (such as the ability I've already mentioned to slice images into separate files, and automatic generation of JavaScript rollovers) and is easy to use. But having to run a separate program rather defeats the simple interface approach of Photoshop - especially when there's a risk you can end up with different versions of images in the different programs.
It's true to say that Photoshop remains the single best all-purpose image editing tool, an invaluable program for anybody who has to handle graphics in a variety of formats or doesn't work purely on the Web. But the simple addition of a separate program that has better Web support doesn't turn the combination into an all round Web wizard - especially when programs like Fireworks 3 do everything the Web designer needs in one tidy package.
I hope that Adobe are working on integrating all of the cool and useful features of ImageReady into Photoshop, because at the moment it's too clumsy.