Don't stop now Riot
It's great that other champs have found their way into the ADC slot, and I i think it's good for the game overall, but why stop there? Most marksmen, especially the crit ones are still kinda stuck in bot lane. I think if we had some items that would help them survive or even thrive in a solo lane we could make this possible.
Early power Rush Item: Stats: 70 AD/20% attack speed Passive: Gain crit chance, up to 50% based on bonus attack speed. (1% AS = +1% crit chance) But crit damage is reduced by 50%. Gaining crit outside of this passive increases crit damage by 0.5%. So you get an early game item that can act as the ghost blade for crit adcs giving them an instant 50% crit with boots, but at the cost of late game power, also gives incentive to continue building crit, so you don't just rush rageblade afterwards.
Defensive Rush item: Stats: 50 AD, 10% life steal 20% crit (Mainly here to make the 3 item build run smoothly. Rushing an item with no crit just delays crit marksmen builds so much, which is why stormrazor didn't help them.) Passive: After taking more than 50% of your maximum health in less than 3 seconds, gain a burst of 50% decaying ms and 10% lifesteal for 3 seconds. (Credits to HàrrowR for the passive idea.) A defensive option for ADCs to take in a rough lane when trying to survive and scale.
Now Crit marksmen can choose to be good early if they so please at the cost of being weaker late, or take a more defensive scaling item that can keep them decent enough to survive in lane as they scale.