I use AOL and Cingular.
Right now I am using Link2exchange so I guess I am sort of a BES.
But it worked BEFORE I was on Link2exchange when I was just a lonely, normal individual user. My 8700 Blackberry and AOL talked very easily right out of the box with the standard Blackberry settings via the "Individual Email Activation" icon.
It is not fast. I believe it has the same 15 minute window to get email on the handheld. It is usually faster though.
but anyway, yes, I do (and always have) gotten AOL email on my Blackberry.