I've been involved with my local makerspace, Tangle Ball in Auckland NZ, for about five years now. The most important thing we have done has been to focus on the social aspect: we're mostly interested in how members and guests behave and relate to each other. So, obviously no discrimination, abuse or other bad behaviour is allowed. We do not focus on any particular technology or tools or activity, but instead think about how we run the place, who gets to make decisions (anybody can take part in debates, no committee with any real power) and who has access or doesn't. We don't exclude any particular activity, anything is permitted so long as it doesn't monopolise any of the resources, discriminate or exclude others.
That said, there are a wide range of activities, mostly around physically making things:
* Boat building
* Debate of social issues such as democracy, privacy, capitalism, urban development
* Software development
* Car painting
* Tool tutorials and safety
* A co-housing group
* A cycle repair group - tumekecyclespace.org.nz
* Cooking and baking
There is a 3D printer, but suggesting a makerspace must have one is an odd and rather arbitrary decision: why would you focus on that one technology, it's terribly limiting? Why not sewing or brass casting or something else?
The question is this: what are you trying to achieve, and why? In our case it was to provide a social space for members, who then provided whatever resources were required. The tools or whatever will follow from there; trying to predict what members and users want will straight away close down what can and can't be done.