Looking at the data and the incoming damage items, I think Shen might need to be looked at.
http://champion.gg/statistics/#?sortBy=general.winPercent&order=ascend
Shen Support: 45.64%/.98% win/pick rate Shen Top: 48.26%/2.70% win/pick rate
Sporting one of the lowest win rates in both of the roles he has stats for (barring that one maniac who goes on-hit, Jungle Shen is pretty much dead), Shen is on a rapidly declining slope in his roles thanks to bruiser buffs, relic shield nerfs, and the heavy nerfs to his ultimate and abilities he received since his rework made him a lot squishier stat-wise in favor of aforementioned utility.
Is he in the absolute worst spot? Of course not. Gragas, Azir, and Ryze are suffering as well, but I cannot pretend that I know enough about those champions to address their issues. Sometimes it's also better that some champions with few weaknesses are kept a bit on the weaker side thanks to their oppressive nature in lane, though I won't go into detail about that. I am here to address a champion I know, so forgive me if it seems I am ignoring other needy champions (like Poppy).
Does Shen have reasons to be kept down in the meta? To be honest, I can see why he can be overbearing in organized play. Teams with high coordination can use an ultimate like Shen's to insane degrees of creativity and it can be difficult to deal with. However, he is suffering on live servers, even in Plat and above, because he just doesn't cut it anymore.
Is it just a one patch ordeal? Honestly, this has been building up for a while. Top lane has Conqueror and will soon have the likes of Atma's returning to add insult to injury, tank supports are only viable through their naturally bulky base stats and inherently oppressive kits (looking at you, Alistar), and junglers need sustain and certain mechanics to clear fast enough to keep up, especially with the new changes to EXP and scuttle crab. And with the advent of the changes allowing ADCs to be dealing true damage regularly (especially when a tank like Shen has among the lowest HP and armor values even among assassins and some mages, let alone tanks), it's no wonder that he won't be able to perform in his roles.
I project that Shen will suffer heavily over the next patch when the new bruiser and ADC items hit the Rift, and I suggest that some of the power removed from him during the rework be reinstated.
I do not advocate we buff his damage at all. He already can duel pretty well if he gets those empowered autos off.
I also do not advocate we buff his ultimate, since all that does is create more misery for us later because of pro play.
I believe the change that needs to be made is higher base stats. HP in particular. Shen, especially in a game with a growing amount of displacement abilities and burst tools, no longer can perform the expected role of a tank as well as his peers in the role. The likes of Sion, Ornn, and Malphite possess exceptional survival capabilities while having sizable windows of power and counterplay. I believe that buffing Shen's bulk to keep up with the new damage options will allow him to survive his lane a bit better, have a more smoothed out power curve, and it will not impact pro play as much because it does not add to his utility, which is his biggest pain point.
That's my two cents on the subject. Feel free to discuss and offer any constructive criticism where needed. And now, for our poll.