This is very true. I'm 20 and I've never used my personal email regularly and I'm sure most of my friends haven't either. We've always used MSN or AIM and more recently Facebook to keep in touch.
My wife's friends are the same way. Sure, lots of them have facebook accounts, but all of her friends and business contacts, new and old, email and gchat regularly. She doesn't even have a facebook account yet and has no intention of ever setting one up.
In fact, I feel less pressure to use facebook these days than I did a year or two ago. I don't even go on it anymore other than when I'm working on apps that use the graph api. My wall is filled with stuff I don't care about and if I want to contact someone I email, chat or text them.
I can see the business & college need for email but for friend to friend communication Facebook messaging is already dominant.