Update 2010-11-18: r1623 is out, restoring the venerable key bindings.
A long overdue maintenance update was released earlier today.
It mainly contains fixes but one change might not please users of European keyboard layouts:
Change next/previous file tab key equivalents to ⇧⌘[ and ⇧⌘].
The motivation behind the change is that Apple are using these keys both in Safari and Terminal (when using the English interface language).
If you dislike the change you can override it via System Preferences → Keyboard → Application Shortcuts.