On the Boston Marathon website it states the following: “Qualifying times are based upon your age on the date of the Boston Marathon in which you will be participating.”
If history continues, for the 2010 Boston Marathon, qualifing times will be accepted “on or after” early October 2008. So if you run a 3:15 marathon when you are 34 years old, but will be 35 on the date of the Boston marathon you are participating in are you considered qualified?
Dave in VA
From FAQ on BAA website:
6. I will be 44 when I run my qualifying race, but will be 45 when I run Boston. What is my qualifying time?
Your qualifying time is based on your age on the day of the Boston Marathon, thus your qualifying time will be 3hrs 30 min – and you can be 44 when you run your qualifying race.
Yes, you get to go 11.5 seconds slower per mile! 
EDIT: OH, don’t forget the extra 59 seconds!
So if you run a 3:15 marathon when you are 34 years old, but will be 35 on the date of the Boston marathon you are participating in are you considered qualified?
Yes. Sweet, ain’t it? 
“Yes, you get to go 11.5 seconds slower per mile!”
Hey, I’ll take all the help I can get since I’ve missed by less than 1/2 second per mile (yes, I ran 3:11:08 and missed by 9 seconds).
Dave in VA
that is the way I read I read it also. I ran my first marathon in November but did not even consider doing the Boston one. Now, I am doing one next month with the goal to qualify. hope we both do and see each other in 2010!
“Yes, you get to go 11.5 seconds slower per mile!”
Hey, I’ll take all the help I can get since I’ve missed by less than 1/2 second per mile (yes, I ran 3:11:08 and missed by 9 seconds).
Dave in VA
missed it by nine seconds? I guess you didn’t want it bad enough…