New Shortcut to Archive in Gmail
Gmail introduces a new shortcut, “e”, to archive emails in your Inbox. The old shortcut, “y”, also archive emails but only works in the sense of archiving when viewing in Inbox (current view) but not in some category (label view). In the lab view, pressing “y” would remove the current label.
You can always check the shortcut help by pressing “?”.
(via Official Gmail Blog)