I believe the SSD on the MBA is technically user replaceable, but it's a weird proprietary format (which some enterprising manufacturer may have cloned, not sure). Sadly the RAM is soldered; the 4GB cap is the blocking issue for me on considering one (thank you, Eclipse).
Doesn't swapping to an SSD should make supposedly 4GB of RAM acceptable? I don't use Eclipse (Dog forbid, I'm an IDE hater) but I can't fathom it needing more than 4GB of RAM. Heck, I run 2 virtual machines, Firefox and my editor on my 2 GB MacBook.
I forget the SSD assist, but I'd have to see it in action before I put cash on it. Eclipse was tolerable with 4 on my last years MBP, but doubling made a world of difference.
