The big addition in this release is an inbuilt PDF viewer. This lets you open the documents as if they were web pages, and while functionality is fairly limited, there are controls to search, zoom and skip through pages. It's also lightning fast, and runs in a sandbox separate from the rest of the browser to help prevent malicious code lurking within the PDF from reaching the host PC.
Obviously there are a huge number of tweaks, fixes and performance improvements as well, and the team has reportedly squashed more than 800 lingering bugs and patched up a few high-profile security holes.
The latest stable version of Chrome is available now, although most users should be automatically upgraded sometime in the next few days. The Dev and Canary builds are also available for the brave and while the beta channel has been updated, it's currently exactly the same build as in the stable channel.