Tried to import a bogus firstname.lastname@example.org account to Mac Mail and I got the message:
"Logging in to the AOL IMAP server "imap.aol.com failed. Make sure the user name and password you entered are correct..."
It defaulted to the IMAP server. So, part of what users I know have been moaning about is losing AOL mail. Possibly they have removed POP to keep up with people using iPads and iPhones to get mail and people are losing mail this way:
Every version of Mail.app going all the way back to the beginning has worked fine with AOL, using POP or IMAP. (One thing to be aware of: If you use IMAP, AOL will delete email from the server after about 20 days. I use a Rule in Mail that says "if any part of the To: address includes aol.com, move the message to a folder called Saved Mail on my local hard drive.)