I'm just curious about this. Since I am trying for this goal, I am basically following what the Hansons do: year-round mileage around 100-120, but a buildup peaking at 130-160 just before a marathon. Racing 1 marathon, one track season, and 1 or 2 half-marathons per year.
I'm not fast but I think I can handle big mileage. Currently I'm averaging about 110 with no real injury problems. I feel like I'll be able to get to 140ish this summer when I'm training for my first marathon.
I've run 8:37 for 3k and 1:09 for the half-marathon, so although I'm not the most talented guy out there, I don't think lack of talent can be an excuse for me.