I dunno, but since I am in Boston I will probably go. Checking out the form though does make it seem like its closed to no Harvard-types.
There are "Non-Harvard" status on the registration form.
It then asks which Harvard professors you are working with.
It says that it is open to the General Public.
I would not interpret General Public to mean persons who have no affiliation with Harvard but are working with a Harvard Professor. That is a little too specific to be considered general.
The registration form is through Google Docs, and they may have failed to customize it for an event that was open to the public.
I submitted a registration, and will see how it goes.
I got an auto-repsonse.
There is a place for "additional message", which you might fill in.