I think the rapid adoption of these first generation cloud type services is basically something that introduces massive inefficiencies and unknowns in to any system.

Simply put, no SLA - even with cash penalties attached - really means anything: you actually have to know the capabilities and specs of your system, its power, cooling and other physical environmental inputs, plus the engineered capacities for live failover on all levels before you can calculate or claim reliability. Anything else is just kidding yourself. A lot of people kid themselves.