What if you ran every distance this year? Started from the bottom and moved to the top.
North Carolina's might look like this:
5K - Run for the Roses 2/7/10
8K - HardCore Serious Trail Runner 2/20/10
10K - Oak Island Lighthouse Run 4/17/2010
Half Marathon - San Francisco Half Marathon 7/25/2010 (totally cheating here, but I like to travel)
Half Marathon - Nike Women's Half Marathon 10/17/2010 (because I do every year)
Full Marathon - OBX Marathon 11/14/2010
Seems like it would be a good gear up for the big one - and keep you on track for the year - and keep your legs fresh.
I'm still trying to pick my races for the year - we'll see if we could squeeze a few in here!