Are conferences places where we repeat ourselves?

It's been a long time since I last blogged and it wasn't part of a class (or at least it really feels like a long time!) Last week I received informational booklets (more than a triptych, less than an actual program book, and advertising in nature) for a couple of summer conferences that I keep track of, and some of which I have attended in the past. Leafing though these booklets I noticed something that hasn't been as evident to me in the past: It's the same people that are in the presentation spotlights this year as have been in the past two, five, or more years! Now, the truth is that I had noticed in previous years, but this year some conferences have moved to a new location (which isn't local), and it was a bit odd to have certain locals highlighted as presenters when the new venue is a 16 hour drive (or 3 hour flight). Thinking back at other conferences too - both ones that appeal to academia, and the private industry of learning design - I've not...