iLevel - Source
450 - Armor purchased with Justice Points (Honoured at various reputation vendors)
450 - Contender's Crafted PvP armor
450 - 88+ dungeon blues/quest rewards and BoE drops
463 - Heroic 5 mans
463 - BoE Crafted Weapons (Blacksmith)
463 - Weapons purchased from Ambersmith Zikk for gold (exalted with The Klaxxi)
--- Rare/Blue above this line ----
--- Epic/Purple below this line ----
464 - Dreadful Gladiator Season 12 Honor gear
470 - Holiday Event Rewards - Brewfest and Halloween will both be shortly after release
476 - BoP Crafted items
476 - Heroic 5 mans (Epic Weapons only)
476 - Darkmoon Card Trinkets
476 - Random BoE world drops
476 - Raid Finder (Mogu’shan Vaults)
483 - Raid Finder (Heart of Fear and Terrace of the Endless Spring)
483 - Malevolent Gladiator Season 12 Conquest gear
489 - Armor purchased with Valor Points (Revered at various reputation vendors)
489 - Epic Quest Necklace (Exalted with Golden Lotus)
489 - Normal Mode raid (Mogushan Vaults)
496 - Normal Raid (Heart of Fear and Terrace of the Endless Spring)
496 - World Bosses (Salyis' Warband and Sha of Fear) *Sha of Fear also drops 483 PvP gear
496 - BoE Crafted Items (Chest and Gloves, probably from Dropped BoP Blue recipe)
502 - Heroic Mode raid (Mogushan Vaults)
503 - Normal “Elite” Optional difficulty Protectors of the Endless
509 - Heroic Raid (Heart of Fear, and Terrace of the Endless Spring)
516 - “Heroic Elite” Optional difficulty Protectors of the Endless