Google has expanded the range of "quick action buttons" for Gmail that let you perform tasks direct from the inbox without opening a message. New options include the ability to directly open a shared Dropbox folder or Google Drive document
Another button lets you automatically open and view YouTube or Vimeo videos from the confirmation messages that appear when an upload has completed.
The remaining enhancements are rather more US-centric (checking out Google Offers or rating restaurants on Seamless or OpenTable). As usual with Google, you may have to wait a few days to see these options in your own inbox.
Take even more actions right from your inbox [Official Gmail Blog]