Color Management Changes in Photoshop CS4
Adobe has made enhancements both big and small throughout Photoshop with the release of the new CS4 version. The changes in the area of color management aren't earth shattering, but they will make your life easier if you know about them.
Save For Web and Devices
One of the longstanding frustrations encountered by those first experimenting with color profiles is the fact most web browsers treat all images as sRGB. If you create a jpeg out of an Adobe RGB image it will end up looking flat and washed out when posted online. Recent versions of the "Save for Web" (and even more recently "Save for Web and Devices") dialog have allowed you to embed the color profile in the resulting jpeg, but it only ends up being ignored by web browsers. Embedding a profile can be helpful in some circumstances, it doesn't really solve the washed out image problem online.
To get around this, it used to necessary to manually convert photos to sRGB before opening the Save for Web dialog. As of Photoshop CS4, there's finally an easier way. With the addition of a simple checkbox labeled "Convert to sRGB" in Save for Web and Devices, Adobe has finally solved this frustration. Most users should simply leave this checked and forget it. From then on, their jpegs will come out right automatically.
With Photoshop CS4, Adobe continues their quest to simplify the printing process. Their quest hasn't always been a straight line towards success since more choices sometimes bring confusion rather than clarity. With CS4 they've continued to tweak the wording and layout in the print dialog to help guide the inexperienced user through the process.
Perhaps the biggest color management change in the Print dialog though is the addition of Gamut Warnings. Turning on this option will show you where certain colors in your image are too saturated or otherwise outside the range of what your printer profile is capable of rendering. This used to be something you had to use soft proofing to get access to and having it directly in the Print dialog is a welcome addition.
Traditional soft proofing will probably still remain my primary tool for making sure colors are optimal before printing though. While the preview image in the Print dialog is now fully functional, it is still rather small when compared to the real estate available for the main image area in Photoshop. Turning on gamut warnings via the View menu after enabling soft proofing lets you see problem areas in much greater detail since everything is much bigger. And since you have access to all the regular adjustment tools this way too, not only can you see any problems, you have the means to address them. Still, having gamut warnings in the Print dialog does provide one last opportunity to make sure things are as they should be before committing an image to paper and ink.
Convert to Profile "Advanced"
The "Convert to Profile" dialog itself is unchanged in Photoshop CS4, but there is now an "Advanced" button that will take you to a somewhat more thoughtfully laid out version of the window. Rather than having to find the profile you are after in a single long list, the Advanced version of Convert to Profile separates profiles by type so you can ignore whole groups of them and focus in on the type you are after. My vote is that Adobe makes this the default in future versions.