You do see people wearing lanyards. Usually not NEARLY as intense as what you'd see at Disneyland where people are wearing thousands of dollars worth of pins around their necks. A lot of times it's families and small kids at WDW. You can usually find at least one person with a book or board out at Epcot at the pin store near the fountain. Sometimes the people there are very honest people just there trading and having fun, sometimes they're the pin shark types who aren't too friendly and try to rip people off. The pin store in Downtown Disney/Disney Springs (have they officially changed the name yet?) is usually pretty busy too.
Just be careful if you haven't done the pin stuff in a while. A LOT of what the cast members have on their lanyards is fake/scrappers (pins that didn't meet quality and were supposed to be destroyed, but escaped the production plants) that have been traded to them from other guests.
Yes I've heard about fakes and scrappers but they say it's almost impossible to tell. Only my 11 year old would be participating so I'm not too worried. Thanks!
Pin Trading is pretty big, though it's mostly with cast members, what I've found. I could go on for hours on where you can find pin boards and books, but needless to say, there are plenty of opportunities for pin trading.