dude, i must live in some sort of blissful la-la land. Haha, me too! I'm not quite sure if I am just not paying enough attention, or maybe I'm just too distracted by shirtless, sex-haired Brian.
I kinda noticed the Gus thing, though now that you mention it I've hunted down scenes for reference: In the 202 Birthday scene, Gus is pretty dark-haired. Then, at the beginning of episode 203, when Brian is talking to Lindsay and Melanie (when Gus first starts to walk), he is very obviously blond. Umm...Maybe Brian got him highlights?