-A/B Split option on the canvas would be amazing!
-Ability to select and move/delete multiple items on the canvas at once. It's a pain to move each step if you need to add or delete something.
-Ability to make a decision based on specific URL's clicks within the email vs. the general clicked email
-An easier way to go into 'test' mode so you can quickly run through all elements of the campaign as a test so no data is recorded before campaign activation.