I've been involved in a couple of maker spaces. One with a lot of machine tools and heavier machines. I've also toured a couple of hot metal oriented shops. My observation is that you really need to let the community guide the build-out and growth. Several reasons: 1. It's hard to predict what people will want until people start using it. 2. You need to have teachers for every tool. 3. Insurance issues will constrain some of your dreams. 4. You want things that people will actually use, because space for tools is a finite resource. 5. Your community may have different tolerance for tool learning curve.
You will find once you start that people will say: "Let's bring in an X." You should ask: Have you used one? Are you expert enough to teach others to use it? If not, can you find someone who is expert enough to teach it? Then after you have a potential teacher, you need to understand from that person the particulars of that machine and whether or not it is a good fit for your community.
Changing topics, here are some things I have seen at different shops, not all in the same shop:
CNC mill, CNC plasma cutter, small injection molding machine (these are all high-learning-curve machines requiring specialist insructors).
manual knee mill, metal lathe, wood lathe.
Sheet metal brakes/punches/english wheel -- surprisingly easy tools to get working with that enable very interesting projects.
Vacuum forming -- simple and versatile.
Hot metal casting -- simple, but needs specialist instructor and special spaces.
Industrial sewing machines and surgers -- enables really cool projects with heavy materials that would kill a home sewing machine.
fiberglass/carbon fiber work set up.
powder coating, paint shop.
glass melting and glass blowing furnaces.
electronics shop for working with surface mount components.
wire welding, mig and tig welding.
I'm sure I'm forgetting some.
Finally: One of my favorite machines is the popcorn machine. I learn a huge amount just by hanging around in the lounge and asking people what they are working on and how they are solving their fabrication problems. You want to build in some space that facilitates interaction.