@Riot, Are you guys making alternatives to Infinity Edge?
For the ADC itemization pass, I mean.
At the moment, we have four different general archetypes when it comes to auto-attack focused champions. OnHit, Hybrid, AD Caster, and Classic Right-Click Spammer. Items for ADCs fall into the IAS/Crit, Lifesteal, Penetration, and Big Crit categories. At the moment IAS/Crit supports all four classes of champions quite well, though Dancer could probably use a little more definition. Lifesteal is pretty healthy, too, though I think doing some work on Reaver to cement it as the AD caster lifesteal item of choice would be great. Penetration just needs a hybrid %pen option to cover all the bases.
Then there's Big Crit...
The only option right now is Infinity Edge, and Infinity Edge caters to the Classic ADC type and sort of to the AD Caster, though not really. For the Hybrid and OnHit ADC it really isn't that attractive.
The reason why things are so stale with ADCs is because one of their major item categories has zero choice involved in it. Are you an ADC? You're going to buy Infinity Edge at some point because there aren't any other options.
You guys should really make a new class of items with the Augmented Critical named passive, one for each of the four ADC styles so champions can buy a Big Crit item that fits with their play style rather than being stuck with a 'one item fits all' stat-stick.
). Kick Trinity Force back up to 15% crit chance and they're golden.
(not confirmed) and the new 
(confirmed) that steals health based on 15% of all the damage you deal and you've got a workable hybrid auto-attacker build.
other than revealing the enemy for 3 seconds, its essentially an infinity edge and another big crit item just means another yasuo rework nerf. removing the steroid THEN making new items that create different strategies is the real answer.
rework:
60 Attack Damage
5% Cooldown Reduction
UNIQUE PASSIVE: Grants you 15 bonus attack damage per 10% cooldown reduction you have.
UNIQUE PASSIVE: Restores mana equal to 20% of the physical damage dealt by your abilities and mana equal to 5% of the magic damage dealt by your abilities.
(1000 G). A has spent 4200 G to get 90 attack damage, 45 movement speed, 20% cooldown reduction, and mana return from ability damage.
Lets compare this to B's build: 
(3800 G) -> 
(400 G). B has spent 4200 G to get 28% crit chance, slightly more than 1 in 4 attacks are critical hits. They also deal 50% more damage with critical strikes. They also have 80 attack damage.
A will have slightly better attack damage, mana return, some cooldown reduction and 45 movement speed while B has an attack between 1 in 4 to 1 in 3 that deals 150% whopping bonus damage. Taking this, I believe it would be fair.