Well I thought all was well in 3.1 beta 3, but it isn't quite there!
Even though you can turn off Anti-aliasing on the Dynamic font, it only appears to affect the editor/stage window. When you run the game, it comes back! Bug? Not sure :(
Here's a screenshot...

Can anyone else find a solution, or perhaps I should report it?
Edit: After a little more experimenting, I've noticed that some fonts have the issue and some don't.