I'm going to jump in, as well. Matt, congrats on the mileage...nice work!
I did a 12K this past summer, slow, but I ran the whole distance, even the hills, which was my goal, so I was stoked. I haven't run anything over 3 miles since then, though. I usually do some kind of run about 5 or 6 days a week, but usually it's just part of my warm-up, so a mile or shorter is typical. I like a long run, though, and am looking for something challenging to do next year, a goal to help keep me focused and eating right, working out, all that. I need a kick in the butt on the running, basically. Running, more than anything, seems to help me with keeping the weight from creeping back on.
For some reason, marathons don't appeal, triathlon, same thing. I'm just, meh! However, I've been reading up on ultras, like 50K, or 50 or 100 miles. Hmm...crazy...impossible...did I mention crazy? I'm thinking THAT would be something, because I can't imagine running that far, I just can't even wrap my mind around that. So, that might be my goal for next year.
I'm still hunting for a potential race to enter. I want a trail run this time, because 50 miles on asphalt and I'm sure my knees would just swell up like pumpkins and I'd fall over dead. I'd rather twist my ankle on a tree root, thank you very much. So, find a run, I'm thinking 50K or 50 miles, dirt, then figure out a way to butter up my trainer at the gym, so he doesn't have a coronary or kill me with his bare hands. He's more of a strength guy, so he's not gonna be keen on the distance running idea. I'd better start saving up the starbucks money for bribes, or learn to bake.
Oh, and in the meantime, I'm putting in one or two longer runs, to start building up mileage and refresh my memory on distance pace. We do a lot of sprint distance at my gym, so if I don't do some distance, I forget how to pace and end up gassing out a few times before I find a pace I can maintain for distance. I'd imagine that for an ultra the pace would have to even a little slower than a 10K pace, but I'm just guessing.