Austin Marathon and Shin Splints

ok, so I had planned to try to qualify for my 4th Boston Marathon at the Austin Marathon next month with a sub-3:30 and was (notice the past tense) having some of the best training sessions I've had in years, and I come down with a shin splint in my left leg (not just the garden variety, the "Who stuck the knife in my leg" type). So now, I've gone from 2 consecutive 200+ mile months in November and December to barely 100 this month and haven't been able to run more than about 20 miles in the last 2 weeks. I'm still going to do Austin, and I have no clue what my time will be, so I'm just going to enjoy myself and do what I can. If by some miracle I can get in a decent 10-12 day stretch of training, I might still have a shot. If I can run the whole way by then, great, if not, I'll walk or crawl or do whatever it takes. You all know the drill. So I may make up my own pace sign that says "3:30-6:00".