glad you find this site usefull, loads of people in loads of fields on here so easy to get 'real world' answers....
to answer ur Q... the fasterping change simply does the following.
as standard setting, Windows gathers information to be sent over the network into little packets before it sends it. basically it means it doesnt always send everything immediatly. (bear in mind we talking split seconds here) now this helps in certain cases like browsing to speed things up. however if your application/game needs to send lots of little bits of information like WoW does, it needs every tiny little bit of info to be sent immediately and right now and not wait for there be enough info in a packet for windows to send it. FasterPing simply disables this 'grouping' and makes your network interface send stuff as soon as WoW tells it to send it. this way you can drop your latency on Wow (i presume all online games) by quite a bit.
Some people do warn that it may affect browsing, but i have not noticed a difference at all in my browsing experience.