On the front page it is shown each wepon comes in three different versions LFR, Normal and Heroic. Now I saw some threads that people made saying something like "OMG LFR gives legendaries" well guess what, it dosen't really effect you as such. From the chain quest you can get the 500 str/agi/intellect gem to put inside your legendary. Now people don't panic about the item dropping from LFR because the only thing that people can get is the gem which is not the legendary.
509 Two-handed Axe Melee Two Hand Shin'ka, Execution of Dominion Sha of Fear Terrace of Endless Spring
509 Gun Physical DPS Ranged Taoren, the Soul Burner Lei Shi Terrace of Endless Spring
509 One-handed Sword Melee One Hand Kilrak, Jaws of Terror Sha of Fear Terrace of Endless Spring
509 One-handed Sword Spell DPS One Hand Loshan, Terror Incarnate Tsulong Terrace of Endless Spring
509 Staff Physical DPS Two Hand Gao-Rei, Staff of the Legendary Protector Tsulong Terrace of Endless Spring
509 Staff Spell DPS Two Hand Jin'ya, Orb of the Waterspeaker Lei Shi Terrace of Endless Spring
509 Dagger Physical DPS One Hand Spiritsever Lei Shi Terrace of Endless Spring
509 One-handed Mace Spell DPS Main Hand Kri'tak, Imperial Scepter of the Swarm Grand Empress Shek'zeer Heart of Fear
509 Fist Weapon Physical DPS One Hand Claws of Shek'zeer Grand Empress Shek'zeer Heart of Fear
496 Two-handed Axe Melee Two Hand Shin'ka, Execution of Dominion Sha of Fear Terrace of Endless Spring
496 Gun Physical DPS Ranged Taoren, the Soul Burner Lei Shi Terrace of Endless Spring
496 One-handed Sword Melee One Hand Kilrak, Jaws of Terror Sha of Fear Terrace of Endless Spring
496 One-handed Sword Spell DPS One Hand Loshan, Terror Incarnate Tsulong Terrace of Endless Spring
496 Staff Physical DPS Two Hand Gao-Rei, Staff of the Legendary Protector Tsulong Terrace of Endless Spring
496 Staff Spell DPS Two Hand Jin'ya, Orb of the Waterspeaker Lei Shi Terrace of Endless Spring
496 Dagger Physical DPS One Hand Spiritsever Lei Shi Terrace of Endless Spring
496 One-handed Mace Spell DPS Main Hand Kri'tak, Imperial Scepter of the Swarm Grand Empress Shek'zeer Heart of Fear
496 Fist Weapon Physical DPS One Hand Claws of Shek'zeer Grand Empress Shek'zeer Heart of Fear
483 Two-handed Axe Melee Two Hand Shin'ka, Execution of Dominion Sha of Fear Terrace of Endless Spring
483 Gun Physical DPS Ranged Taoren, the Soul Burner Lei Shi Terrace of Endless Spring
483 One-handed Sword Melee One Hand Kilrak, Jaws of Terror Sha of Fear Terrace of Endless Spring
483 One-handed Sword Spell DPS One Hand Loshan, Terror Incarnate Tsulong Terrace of Endless Spring
483 Staff Physical DPS Two Hand Gao-Rei, Staff of the Legendary Protector Tsulong Terrace of Endless Spring
483 Staff Spell DPS Two Hand Jin'ya, Orb of the Waterspeaker Lei Shi Terrace of Endless Spring
483 Dagger Physical DPS One Hand Spiritsever Lei Shi Terrace of Endless Spring
483 One-handed Mace Spell DPS Main Hand Kri'tak, Imperial Scepter of the Swarm Grand Empress Shek'zeer Heart of Fear
483 Fist Weapon Physical DPS One Hand Claws of Shek'zeer Grand Empress Shek'zeer Heart of Fear
Now assuming you get the gem from LFR you can put it in the LFR wepon, normal or heroic so people wont be runing around with legendaries because there are three phases. The only thing that LFR can give you is the item for the gem, not the legendary.