I imagine people are going to buy gems so they can buy character slots immediately.
like Guild Wars 1 there can only be one person across all servers with the same name. there can only be one totalbiscuit.
I think people are going to quickly make characters so they have dips on short popular names with no last names like "Neo" "Legolas" "Sims" "John" "Avatar" "Chair" Those short iconic name. this is diminished in other mmos because people can be named the same thing.. on different servers.
But across all worlds in Guild Wars 2, there will only be one guy named John.
my little brother wants to name his characters after the ninja turtles, so as soon as the headstart begins, he will see if he can make rafael, leonardo, donatello and michaleniolo and probably splinter (the rat). he wont have time to go through the customization, he just wants to have dips on the names as he think this will make him more recognizeable as he will try to make his mark on the community.
I think a lot of that is going to go around. its the one word names that really mean something because people with first and last names can be difficult to spell or remember correctly and its more complicated to /whisper or /mail or shout or add them to friends or talk about them in e-sport terms. but people will remember the one guy called nothing but John, hehe.
Personally I am going to try and get the name "Toilet". I might have to buy an extra slot just to have that name for a joke character. I think I will just roleplay him as a sort of melandru-ish version of jehovas witnesses. I just hope males can wear dresses in gw2.
edit: i did a test of this; you can name a character something and delete him, and immediately make a new character with the same name. i didnt experience that classic "the character name is unavailable"