It would be helpful to be able to view the results of list imports at any time. Currently, when importing a list, you have the option to send yourself a notification that delineates the number of total, new, and existing records imported from that list. The issue is if you don't elect to send yourself the notification before the pop-up window disappears (by the time the list finishes importing), there is no way to retrieve the breakdown of the results of the list import.
I've found a workaround to determine the number of new leads imported (create a Smart List with the filters "Was Added to List" and "Lead was Created [Date of Activity]"), but it has many limitations. It would be great if Marketo automatically created an archive of list import results.