I mean I know we're kind of freaks here. But I probably have 40-50 people with iPhones on my contact list, and while bored at work I just went through and a grand total of 3 have upgraded to iOS5 (you can tell because they don't have iMessage yet). 1 is a programmer and another one I told about iOS5 and did it for her last night. I guess it's possible that more than a couple are upgrading their phone and don't feel like the hassle until they get their new iPhone anyway. Related side note: is there anyway to get a list in your contacts that is just people with iMessage? Seems like it would be a useful feature.