As a newbie, I'm a bit ambivalent with respect to this topic.
I found geocaching by accident - and I'm so glad I did. I'd hate to deny the pleasure I've had geocaching to other people, but I'm worried about what the sport might become once it has become mainstream.
There are two factors involved in this:
1. The price of GPS units are coming down at a drastic rate. I picked up a new Garmin Etrex Camo for about £70. This is affordable for most people.
2. Information wants to propagate. The prevalence of the internet in people's homes allows access to sites such as www.geocaching.com. That coupled with increased media coverage and affordable gps units can only increase the number of people enjoying the sport.
So what can the community do? In other scenarios (such as adoption of desktop Linux or BSD), the old guard become hostile to "newbies" and refuse them help until they've proved themselves to be True to the Way. This is bad.
Alternatively, they can welcome the new members with open arms and allow what they do to become diluted to the point of extinction. This is also bad.
How does a community cope with a massive influx of new blood?
Darwinism - adapt or die. Harsh perhaps, especially to the founding fathers (parents?) of something special (like geocaching).
Is there another way? I hope so!