I'll buy this next MacBook Air coming out whether it has these things or not, simply because I want a lighter laptop because ever since I saw ads for the original Sony VAIO memory stick laptops back in the day, I've wanted a 11" or so laptop!
But I will be devastated if it doesn't have a backlit keyboard. I don't know what it is, but it's almost like a 'can't live without' even though I catch my current MacBook Pro dimming when I don't want it to, effectively making the backlight useless until I trigger it to brighten up.
Also, you'd think Thunderbolt is a given, so no need to request that.
USB3 would be nice, but I understand that might be something to do with Intel's next chipset or something?
Actually faster SSD chip would be great (SATA3 equivalent).
Sandy Bridge CPU seems a given.. surely!
More battery life would be nice
End of the day, I'll get whatever comes out, but it's the things listed above which will make me either content or super happy!