TedC in talking with Loree:
To delete the contacts and the list: Go into the List, "select all" of the email contacts in the list. There is no option to keep them in the account going this route (see below). Then delete those contacts; then you can delete the list.
To delete the list only: go to the list, select the list, and then choose delete it. You will then see a notification indicating that contacts remain, even though the list will be deleted.
There is always the option to click under your name in the upper right, and you can toggle to the old interface.
Above per Loree, in Support. I read this back after typing it, and he confirmed I had it right!
