Old Contact: Click add contact button -> Type email address -> click which lists -> Submit.
New Contacts: Click to few a specific list -> Click add contact -> Add email -> click ok -> open a screen where you can choose which lists -> Submit.
So, why was the add contact button removed from the first page in Contacts? The screen that the add contact button brings up is all you need to chose what list(s) a single contact gets added to.
Also, what is the point of the small email address pop-up when you add a contact when the next window is just going to be the one I posted above where you can just type the email address in and not have an extra, pointless, click before getting to the window that actually gets something done.
Since the add contact window still has a checkbox list for adding a new contact to whichever lists you have, what difference does it make what page you access that window from?