Tanks.
Think about it. We got ADCs, we got assassins indirectly (and then Duskblade), and we're getting mages? To avoid making this meta a huge stat-check of DPS, it would only make sense to give tanks the push they need to do their job. They get blown up too easily and feel obsolete, unless when seriously ahead.
I might be biased on this, but it makes sense logically. If not tanks, then at least look at supports.
BeatzBoyFTW4 votesTank meta was last years.
Melledoneus1 votesIt's a cycle. ADC into assassin into mid lane meta into tank meta. It's only a matter of time.
ModWulf Helhammer1 votesDuskblade isn't the assassin class pass over. It was simply an item to help balance AD assassins in the future
Melledoneus1 votesThe assassin meta came with the ADC meta. It's kind of like how Vayne became uber popular in the tank meta.
Elindiir1 votesRight now, tank supports are pretty strong... With the strong tendency for mostly AD teams, stacking 500 armor means that even with 40% armor pen + 60 still leaves 200+ armor... Enough armor to still make it hard as hell to kill. On top of that, thornmail with this much armor will cause an enemy ADC to commit suicide on you.
Melledoneus1 votesWell, I was speaking exclusively about jungle and top lane tanks. Supports will be supports.
Also, stacking 500 armor is highly unrealistic for most tanks, and the fact that carries almost always buy lifesteal undermines thornmail's damage quite a bit.
Also, there are many, many AD assassins that don't even auto, and Duskblade makes it so much easier for them to kill you because of how much armor pen is available through itemization. Not to mention the massive execution bonus on the item that can execute from 15% HP or lower, easily.
Also, tanks don't have any way to deal with devourer junglers who virtually melt them. Especially Xin Zhao. With decent itemization, tanks could become more central to a team besides in the support role and the LCS.