Pretty cool man, I assume its much easier to play using that layout? If you memorize it, that is.
It helps for Role Playing. I can quickly do an appropriate Emote (hit one key instead of typing "/tantrum"). The most useful though is the row of Pet commands. I play a "Lore Master" who has familiars, and it's quite complex to manage your own character in addition to the Pet. This way I can quickly tell him to Attack, Guard, etc. They all are tied to commands (i.e. "/pet attack"), so it's much faster to just hit the key.
And did I mention they are Cherry Browns?

The keycaps are relegendable, but you could substitute regular caps if you like.