Google has just added updated its stable browser channel. Version 16 takes the profile manager live and adds enhancements to the syncing.
Chrome 16 is the eighth release for Chrome this year. The big news is multi-profile support in one browser window. You can simply add new user profiles by clicking the user icon on the top left of the browser window or via the Tools/Options menu. This new feature enables multiple users to use the same browser window and load their browsing history as well as bookmarks (a carryover feature that previously required a retired Google Gears feature), as long as they are synced. What you can't do is run two profile in parallel at the same time.
Google also added 15 (published) security patches and paid $6000 to those who discovered them. The nightly Chrome (Canary) has arrived at version 18, which recently introduced an overhaul to the extensions page, which is still very much work in progress.