I suggest that PvP rank (or possibly faction) should be usable to unlock new armour, dyes and weapon skins for PvP only characters.
For example, at rank 6 you would allow to create PvP only characters with 15k armour skins, and at rank 9 fissure armour skins. There could also be a system that allows you to use different weapons skins to the default PvP ones at higher ranks.
eg.
Code:
Rank Sword Axe Hammer Armour 1 Falchion Great Rams 1.5k 2 Spatha Battlepick Foehammer 1.5k 3 Dragon Hand Axe Runic 1.5k 4 Flamberge Cleaver Break 1.5k 5 Wingblade Summit Twin 1.5k 6 Longsword Chaos Summit 15k 7 Brute Sephis Righteous 15k 8 Fellblade Tribal Mursaat 15k 9 Crystalline Dwarven Ball FoW 10 Serpent FoW 11 Sickle FoW
Dyes should also be unlockable, this could be done either by rank, or what I think would be a better solution, to have them unlockable by faction, as It's something for people to spend faction on once they have unlocked everything else. It could be 3000 faction to unlock each non-default available dye and each mixed dye, this would allow lots of different dye combinations to be unlocked so a long term use of faction spending, but would also mean players could unlock their favourite dye combinations fairly quickly.
Item skin unlocks could also be done as faction unlocks which would be much easier to implement into the current interface system, it would also reward non HoH PvP players. I think for this to be done the maximum available faction cap would have to be greatly raised from 10,0000, and FoW armour and rare weapon/shield/staff skins made very expensive to purchase in faction to help maintain their exclusivity.
I believe these changes are in keeping within the apparent Guild Wars goals, keeping a level playing field for all new characters, so especially with the new faction changes and priests of balthazars in arenas there is not much time investment to be competitive, but also providing rewards, even if only aesthetic ones, for players who invest time into the game and keep the community going.