Making RAM virtually non-user-serviceable on a desktop is terrible for a number of reasons, chief among them being the fact that modern RAM chips have an absurdly high failure rate. A situation that is tolerable given how cheap new memory is but largely offset in this case by how difficult it is to do the replacement.
Same for the Retina versions. Bought a non-retina Macbook Pro a couple of weeks ago before they stop selling these.
My last Macbook Pro lasted almost 7 years because I could upgrade from 1 to 2 GB. Without the upgrade option I expect the halflife to be notable shorter.
Don't worry. The fanboys will still be fawning over it like it's the greatest "invention" since sliced bread