@figuerres: That's very similar to my own conclusions after investigating this stuff. Until the elastics can offer a compelling price point to the little guy for 24/7 or maybe some kind of sliding time share with people on the other side of the world, the only legit use case i can think of would be on-demand cpu cycles... like if you wanted a super computer to crunch serious numbers for one specific task, without investing in a bunch of ps3's/graphics cards and actually building the super computer.
I can only assume they offer better economies for general hosting when you get past a certain scale.
Thanks for all the suggestions, everyone. It's interesting to see who people are actually using.