Honestly, I think they're being smart to discontinue the 8gb version, even though you can add seemly unlimited space to the console through external storage, with how many people are going with digital only copies, many people would fill that up in no time, not to mention DLC etc etc. Although if you're strictly using disc based games and could care less about DLC or any of that, then 8gb would be fine, but I feel like there's not enough of a market for it honestly.
I work at staples and you want to know what the smallest size sd card and usb flash drive we offer is? If you guessed 8gb, you are correct! Its a sign of the times, 8gb doesn't cut it for most people....