sonys biggest rip-off at launch was that the bump between systems was only 40GB...if the 60GB was 80 or more it would've destroyed the 20GB....i still love my 60GB but value wise they could've went higher with a larger HDD than that between the $100 bump
that said, built in card slots and WiFi makes it a better choice anyways (wifi was the biggest), add in an extra 40GB on top of the 20GB and i knew right away which one i was buying at launch
and if you mean as in a collector's sense...doubt it, i think this will be the big system trend (multiple SKU's)...until there is just one platform period (which is a ways off still) and they really aren't that rare
besides most systems aren't much collectors wise anyways unless they are sealed or in pristine condition (and even then they still aren't worth much), its not like games or other collectible stuff where they might end up worth more than they cost