Font rendering changes?
I'm really surprised no one noticed that the font rendering is completely different now. While large letters look much better now small letters really look horrible.
Monaco 10pt font rendering with antialiasing (white text on black bg) is really hard to read now because it's rendered as a grey smush on black (like the first
antialiasing attempts under Linux 10ish years ago):
iStat Menus 3 has the same problem
as does Growl and all other applications displaying bright text on darker background in small fonts.
Dark on bright also looks quite different those the results are a bit more pleasant.