Well having a fixed limit and having no central authority are probably two of the most important aspect of bitcoin.

At first I was worried that if a big player like amazon made a move backing their currency with their inventory, they could basicly position themselves as top dog in a new currency... but following that logic, the economy around airmiles and canadian tire money http://en.wikipedia.org/wiki/Canadian_tire_money is already bigger than bitcoin but no one would seriously think of usethem as everyday currency.