Welcome to the world of crappy font rendering for the majority of browsers. Even with @font-face in the wild, it's going to be years before we finally see properly rendered fonts for our end-users.
Something that's helped us: adding "text-shadow:0 1px 1px #FFF;". Particularly useful with webkit. Adding the drop shadow ratchets up the perceived anti-aliasing, even if the text is on top of a white background.
This was exactly what I first thought. To make things worse, I hate Apple, and so I immediately associated your product with all the problems Apple has caused me.