Two character ones are for countries, though. What would you do if a private entity owns ".op" and a hypothetical country of Opzerkistan declares independence?
As for domain hacks, I think many laypeople just enter "something.com" without thinking too much. Remember whitehouse.com[1], in the 90's?
I suppose the same thing that would happen if there were two independent countries that start with "Op"... right now there is no ".op" domain and that makes me sad.
True, but they would simply assign them different two letter TLDs. For example, compare Montenegro (.me), Macao (.mo), Mongolia (.mn), Malta (.mt), Madagascar (.mg), Mauritania (.mr), etc.
I can understand how it would be frustrating, though. For a long time, the TLD for my last name (two letter last name) wouldn't allow second level registration.
As for domain hacks, I think many laypeople just enter "something.com" without thinking too much. Remember whitehouse.com[1], in the 90's?
[1] http://en.wikipedia.org/wiki/Whitehouse.com