I just checked mailing list stats for our largest UK customer - where AOL never reached penetration anywhere near the US - and while AOL is by no means huge, they're the fourth largest e-mail provider represented on their list, after Hotmail (which out-distances everyone by a wide margin in the UK) and Gmail / Yahoo (which one is in second depends on whether you count Yahoo's various partnerships - they provide e-mail and other content services for some major ISPs).
Techies in particular tends to get very surprised when they realize that the entire world don't use Gmail... (gmail accounts for about 9%-10% of the subscribers on that list, compared to about 35% for Hotmail...)
This is a restaurant chain that covers a pretty good cross section of the UK, with a list of near a million users.