I never understood ATM. I must not be part of the target audience. Now that 100base-T is here, I get it even less. I heard a speaker from the ADSL forum lately who claimed that ADSL would eventually be all ATM. That does not make sense to me.
Sometimes I wonder if the phone companies of the world have been tricked into believing that they want ATM only to find out that what the customers want is large packets (not 48 byte payloads) and that their networks are setup all wrong.
I'm planning to look into wireless-ATM next, just because anything that sounds that twisted might actually be interesting.