In a multi user environment (thousands) there will always surface things that an in-company test group can´t possibly find out (time, resources, sheer number of players etc.). That applies to any kind of release, big patch, expansions etc.
I am actually totally amazed that a massively PvP product like NW with all the land-control specifics has gone down as well as it has done. It must take a minimum of 40 skilled people to "really" test the balance (probably 100+) . Yet, no heavyweight "fixes" have been necessary since day 3 or so after release, just some tuning and enhancing. Good job I´d say!
Personally I prefer "fix it if you know it´s there" rather than "let it slide and fix it.. later." That´d piss me off.