I don't like the soldered RAM and SSD chips either but the battery can be replaced by Apple:While I understand that the built-in SSD and RAM make the machine more portable, I'd be afraid that would also make the computer essentially disposable.
With this new computer, Apple is essentially stamping an expiry date on the back. Eventually the battery will die, eventually you'll decide that you need more RAM or storage space, but this time there's no way to upgrade anything, so you'll have no choice but to dump it and buy a whole new machine.
http://www.engadget.com/2008/01/15/macbook-air-battery-replacements-129-free-install/