So far I have found 2 Pokemon to be utterly borked at the moment and I feel should go. The first one is Terrakion, which I do not feel I need to elaborate on as everyone is already starting to repeat themselves.
The second one is actually Serperior. With the tier shift Serperior lost a couple of its faster threats in Scarf Jirachi and Starmie who could carry Ice Beam, as well as a nice defensive answer in Celebi. And although at first everyone looked at it and thought it was easy to check or counter, since people have had time to play with it and experiment with it I find this no longer to be the case. I find that it can be really hard to switch your check into a Serperior, as surprisingly it is actually quite versatile. Besides the obvious Leaf Storm that will be on every set, Serp can run Glare, Dragon Pulse, HP Fire, Substitute, Taunt, Synthesis or even Dragon Tail to prevent being phazed. Checks like Crobat are greatly crippled by Glare. Things like Goodra get worn down by having to constantly take Dragon Pulses. Defensive mons that rely on a status move or something to deal with Serperior can be subbed on or taunted and become setup up galore, not to mention very few defensive Pokemon in the tier have something to hit Serp back hard. Scarfers also have to watch out for Glare and Sub. In a lot of cases you can easily lose a Pokemon when Serp switches in at the right time before you can get your answer in, and even then Serp can easily switch. Serps great speed at the moment, coupled with quite useable bulk, ways to get around checks and of course great boosting potential in Contrary Leaf Storm make it very overwhelming with only a tiny bit of support, and I believe too strong atm, which is quite different to how I initially saw it.
Salamence I am uncertain with, but I think it would help to have a closer inspection once these 2 mons (or at least Terrakion) leave the tier.