It's great that Fred's publicly supporting the foundation. For one thing, it means Fred likely holds a decent amount of BTC himself.
He didn't publicly Support the foundation, cause he never tweeted, or blog posted about it. How do we even know if that was suppose to be anonymous donation, and they outed him. I really think Fred Wilson should write a blog post. Also how do you know he holds any bitcoins, remember bitinstant is part of the foundation how do we know he just brought 500btcs and instantly gave them to the foundation, and bitinstant waived the fee.