I guess the difference is basically this, then, when broken down:
会える -- you can't yet meet them and are looking forward to being in a state of being able to meet them.
会う -- you haven't yet met them and are looking forward to being in a state of having met them.
The focus with 会う is more on being in the same place with them at the same time, whereas with 会える it's more on that being a possibility. Does that make sense?
Alright, so I guess that's just a different way of stating what Mike said.