State of Top Lane & Bruiser Keystones
A lot of you have probably watched Hashinshin's rants regarding the state of the game (specifically surrounding Top Lane). One thing that always stands out is that he claims that there isn't a bruiser keystone. As a quick side note, I personally think Hashinshin has a very large bias towards wanting bruisers to be the strongest champion type. He exclusively plays bruiser type champions like Jax, and wanting your main champion to be stronger is quite the incentive to use his popularity and stream to get support for a top lane overhaul.
So the main problem is that there isn't really such a thing as a bruiser in League of Legends. The closest we have by game definition are the Fighters, but the list of Fighters is so versatile that you can't exactly cater to any one type. Lee Sin, Riven, Gnar, Darius, and Jayce are all considered Fighters, and yet they're all completely different in their play style both in lane and in team fights.
Hashinshin makes a point to rework press the attack to be personal damage instead of damage from all sources and be two hits instead of three for melee, however if Riot implements these changes, champions that are auto attack heavy (Jax, Aatrox, Irelia to name a few) will get a significant boost to their damage.
This wouldn't particularly be a problem in their lanes, it would likely give them the boost they need to challenge lane bullies like Gnar and Gangplank in an all in engagement. However, by the mid to late game when small scale skirmishes and team fights start to break out, these champions will still retain that boost of damage, and will be significantly more lethal.
A few examples; Riven can buffer her Q and auto attack inbetween casts to proc press the attack for bonus damage on the third Q and third auto attack. Most Rivens already auto attack inbetween Q casts so there isn't exactly a change in mechanics, just more damage for practically free.
Both Jax and Aatrox can proc press the attack and cause their empowered auto attacks (from their ultimate or W respectively) to deal more damage. Again, this isn't a mechanical change because both champions are auto attack based anyway, so it's just more damage for free.
Bruiser type champions also tend to snowball off the smallest leads in the early game. This isn't particularly an issue, if someone gets a lead in lane they should have lane dominance. However, I don't think that a single kill should put you so far ahead that the lane becomes one-sided. This is an issue in other lanes as well, but it's specifically annoying in top lane because the match ups are almost exclusively melee vs melee, meaning just to get CS you put yourself in danger of getting all inned.
TL;DR, There are far too many champions that constitute as bruisers and most of them have a different play style than the last. This essentially means that a Bruiser Keystone cannot exist. If one did exist it would likely push bruisers into a carry position instead of a sustained DPS / Off Tank.
Feel free to post your thoughts, I'd be glad to read them.