Still annoyed that I can't drag an image from Firefox to Photoshop via the OSX dock, despite the fact that it's been a known bug for ages.

Otherwise, it does feel faster, though I find it funny that Firebug currently doesn't work even though it's prominently listed as one of their main developer tools.

They worked really hard on making the add-on interface more intuitive and cleaner, but really the thing everyone wants is better memory management.