Yes moony there are some "warm up tents" alongthe route. It is sad that the weather is so crappy. There has always been a carnival like atmosphere along the way and the runners love it. Sadly most folks are opting to stay warm and dry.
There are banners hanging along the streets of Boston. On them are printed quotes from the "everyday" runners on why they run Boston. My favorite was "To hear Wellesley (the college people!) scream"
"All I ask of you is one thing: please don't be cynical. I hate cynicism -- it's my least favorite quality and it doesn't lead anywhere. Nobody in life gets exactly what they thought they were going to get. But if you work really hard and you're kind, amazing things will happen."
Conan O'Brien