I was just thinking about this... and here's what I came up with.
back to my mac using AT&T's cellular network, anywhere in the US, free to .mac subscribers.
32 or 64 gigs of flash memory. (w/ option for additional 1.8" HDD)
13" screen
5 hour battery life
LED display
Aluminum exterior
1 gig DDR2 RAM
$1200
external optical drive, or simply connect your mac to a mac equipped with an internal optical drive via firewire and use that mac's drive.
Full OS X
Discontinuation of the "Macbook" line. Now, you can have a Macbook Air, or Macbook Pro. No Macbook, just like there's no Mac.
OR.....
back to my mac using AT&T's cellular network, anywhere in the US, free to .mac subscribers.
8 or 16 gigs of flash memory.
11" screen
3 hour battery life
LED touchscreen display
Aluminum exterior
512mb RAM
iPod touch version of OS X
external optical drive, or simply connect your mac to a mac equipped with an internal optical drive via firewire and use that mac's drive.
$500
But somehow I don't think Apple is going to be releasing a Macbook Air anytime soon...