I've read that publishing your goals publicly improves the likelihood that you'll accomplish them.
So there you go: 5K, 10K, Half Marathon and Marathon goals, respectively, for 2013.
I can't emphasize enough how far from these goals I am right now. I struggled to run 40 miles last week, and I've lost a lot of fitness in the last two and a half months. But I've got 15 months to get there, and, assuming I get healthy between now and December, I plan to do -- consistently -- real workouts throughout 2013 (as opposed to just lots of aerobic running), which is something I haven't done in 16 years. I'm hopeful that this will produce real results.
If anyone is out there on the interwebs and has an interest in joining me for some of these harder-intensity runs, let me know. It'll be a few months yet, but it's always good to have someone pushing you when you're trying to run hard.