Version Cue, Adobe's server-based version control and file-sharing management tool became quite easy to use with the CS3 version, so it was safe to assume that the CS4 upgrade would remain essentially unchanged. In many ways it's true: Version Cue CS4 is largely unchanged.
But in a few key ways, it has changed dramatically. The result is that Version Cue is now less complicated to use overall, but it requires more steps for users to take advantage of its file-sharing features. The updated project manager no longer complicates suite apps, and leaves what already worked well alone.
Note that when Creative Suite 4 shipped last October, Version Cue contained a bug that rendered the new version nonfunctional (Adobe disabled Version Cue in the original CS4 shipping version). Later, it released the 4.0.1 update as a free download and this analysis is based on that updated, functional version.
The biggest change in Version Cue CS4 is in its client software, which ships with the following bundles: Adobe Creative Suite 4 Design Premium; Design Standard; Web Premium; Web Standard; and Master Collection. It no longer adds a parallel universe of dialog boxes in the various CS4 programs, as did previous versions. Gone is the Adobe Dialog button in Open a File, Save As, and other file-oriented dialog boxes that let you manage shared files in a workgroup.
This change simplifies the dialog boxes, ending the confusion as to whether you need to have them set to display Version Cue functions, such as creating new projects and undeleting files. But the price for that simplicity is that you no longer manage projects from within the various CS4 applications while you use them. Instead, you must switch to Adobe Bridge to manage the projects that comprise your shared files by choosing Tools > Version Cue (and first enabling the Version Cue start-up script in the Bridge preferences, as it is not on by default). That's not a terrible burden, but it does tend to make using the project-management features less convenient. You can still access Version Cue servers via the Open, Export, and Save As dialog boxes in each application, but there are no longer separate VC-enabled dialog boxes to switch to as in CS2 and CS3.
On the plus side, Adobe has made it easier to find the shared files. Before, you could access them only from an Adobe app such as Photoshop or Bridge. Now, these shared files appear on your desktop as if they were network drives, so you navigate to them as you would any other file share, using the standard Mac commands. Ditto for adding, renaming, and deleting files. This change makes the use of Creative Suite projects more intuitive.