Ohhhhh...someone's getting testy!!!! Put the koolaid down for a second son.
The iMac still looks the same as it did before the thinness. All they did was make it thinner. I'm not dismissing that this wasn't easy, I'm just saying the overall design is the same from the front. It could use a facelift with something new.
I don't care if the majority of sales are notebooks, that doesn't mean you ignore the rest of the lineup. People still buy iMacs, Mac minis, etc. The Mac mini currently is shameful for what you get for the price.
What kind of thing were you thinking about? In what areas do you feel the iMac needs to be changed / improved? The reason the iMac remains much the same is that by now it has been pared down to a screen, essentially. Would a colour change constitute a 'facelift'? In my opinion the present iMac has come a very long way since 'before the thinness', whenever that was. It can still get thinner but a 27" screen will always be a 27" screen. I remember some poster said prior to the iPhone 5s that Apple needed to up its game to beat Samsung. He thought Apple shouldn't incrementally improve the iPhone but instead "innovate and completely blow our minds". Not that I don't like having my mind blown by new design but it is hard to see how the iMac, or the iPhone can possibly do that through exterior design at this point. One day perhaps, the iMac will be a thin piece of clear class that will only function as a powerful computer (screen) once it is has been woken from sleep. That technology is a little way's off, though, I think :)