Every user of a Canon digital camera that produces RAW images should get this update and install it as soon as possible. The EOS Viewer Utility is much more pleasant to use and it is significantly faster. All information is displayed well integrated - the only annoyance is the file tree that is still laid out far too thick, which never fits into the small area if you've created larger directory depths. But you can now hide it by pressing a key.
It's also annoying that you still can't open the EOS Viewer Utility with a start file under OS X - even with the new utility, only the folder of the image is opened as an overview, not the specified image directly. For integration with iView Media Pro, that's not exactly optimal.
Otherwise, it's definitely generations ahead and better than the old File Viewer Utility.
By the way: contrary to its designation as an English version, the updater also contains a German translation - at least under OS X.
At PhotographyBLOG you'll find the original article.