Ridgerunning for the AMC in 1996 cured me of wanting to thru hike the AT again,in season anyway. you can tell just how many people are really on it when you hike the same section all summer, wave after, wave after wave of groups of hikers. I seem to recall clumps of hikers down south when i thru hiked but by the time I hit central Virginia everyone was really strung out and only grouped up in town. When i was ridgerunning there were large groups that had been together for 100s of miles, I'm just not that social. Maybe it's on a bubble? i don't know. I think it's interesting that the % of hikers that finish a thru hike stays basically the same no matter how many attempt each year. I think I read at one point that in 1995 there were 2500 people attempting a thru hike. How many were there in 2010?then go back another 15 years to 1980? huge differences, so in short, I'd say it's getting crowded, at least down South, too crowded? maybe. But the weekenders and section hikers still make up the majority right?