With a timing that seems almost as peculiar as the product itself, Canon officially released the RA-E3 Remote Controller Adapter today.
The RA-E3 allows cameras with an E3-Type socket to connect to remote controllers with an N3-Type connection (as seen below).
For what it's worth, the price of this adapter is only slightly less than the purchase of a dedicated Third-Party Timer Remote Switch with an E3-Type (sub-mini) connection.
B&H has the Canon RA-E3 Remote Controller Adapter available for preorder.