The "&" before "Bookmark manager" is Windows' system of making the next character underlined and a shortcut if the menu is open. (The Gtk equivalent is the _ character.) This seems like it's directly using Views instead of Gtk. The other numerous menus, such as the status area, page, wrench, and tab menus still use Gtk.
Also, the "Create application shortcuts..." dialog has changed to be like the about and external protocol dialogs; it's directly using Views.
I'm guessing that the code is shared with the Windows code, because I doubt that they'd rewrite it and include 'Desktop' since Chromium OS does not have a traditional desktop. However, I wouldn't be surprised if the 'Applications menu' stays and actually adds it to the main menu currently hosted on Google's servers. Personally, I quite like the appearance, if the X button were to be positioned a bit lower.
Also, the Chromium OS file browser added an option and an icon for uploading pictures to Google's Picasa Web Albums. (I couldn't find it in the interface.) Chromium OS' platform is the web, so tight integration with it is essential. If more additions like this one to the file browser come, we could essentially have the famous "Google Drive."