I assume this is for the tier that the pokemon of the week is usually competing in. For Salamence this is OU indeed, since it's waay too strong for UU and almost completely outclassed by Rayquaza in Ubers because Ray has harder hitting attack stats, slightly better bulk not counting Intimidate, and ExtremeSpeed.
Anyways, I think that Salamence, hasn't changed all that much in the generation shift, although it did get Dragon Tail and Hone Claws.
First a Hone Claws set I made up:
Salamence @ Life Orb
Trait: Intimidate
EVs: 4 HP / 252 Atk / 252 Spd
Nature Adamant (+Attack, -Special attack)
- Hone Claws
- Dragon Rush
- Stone Edge / Dragon Tail
- Earthquake
Hone Claws boosts Salamences attack up and gives it an accuracy boost. After a single boost, Dragon Rush and Stone Edge are both 100% accurate. Stone Edge + Earthquake is good combo and Dragon Rush is powerful STAB, more powerful than Dragon Claw. Outrage can't be on this set since it clashes with Dragon Rush as Outrage comes from platinum whilst Dragon Rush is a 5th gen egg move. I think Fire Blast is a good move to put in this set as well instead of EQ or Stone Edge to deal with Skarmory, and it also gets an accuracy boost from Hone Claws.
Dragon dance is old stuff, but it still works:
Salamence @ Life Orb
Trait: Intimidate
EVs: 4 HP / 252 Atk / 252 Spd
Nature Adamant (+Attack, -Special attack)
- Dragon Dance
- Dragon Claw
- Earthquake
- Stone Edge / Dragon Tail
Simple Dragon dancer that also worked in 3rd gen and 4th gen. Dragon tail is a fun move that is basically whirlwind that does damage, so it can pick up additional entry hazard damage. It's less good as a primary STAB move since its base power is rather low and it always goes last, but it's great fun when the foe switches. When a foe switches in a counter, Dragon Tail hits their counter, damages it a bit, and then immediately sends away the counter. Basically, if your foe switches and you use it on the switch. It results in the foes counter being damaged and the foe still not having their Salamence counter in play. With entry hazard support it's even more fun.
Next up, Choice Band:
Salamence @ Choice Band
Trait: Intimidate
EVs: 4 HP / 252 Atk / 252 Spd
Nature Adamant (+Attack, -Special attack)
- Outrage
- Earthquake
- Dragon Claw
- Stone Edge / Dragon Tail
Still a good choice I recon. Outrage is a fun bulldozering move that hits hard. Dragon Claw is a reliable move that allows you to switch out whenever you want, so you don't get destroyed when Aggron for example switches in on Outrage and uses Stone Edge.
Choice Specs:
Salamence @ Choice Specs
Trait: Intimidate
EVs: 4 HP / 252 SAtk / 252 Spd
Nature Modest (+Special Attack, -Attack)
- Draco Meteor
- Dragon Pulse
- Flamethrower
- Hydro Pump
Basically Specs-Mence from the 4th gen. On the special side Salamence hasn't changed at all in the gen shift.
Choice Scarf, mixed set:
Salamence @ Choice Scarf
Trait: Intimidate
EVs: 252 Atk / 252 SAtk / 4 Spd
Nature Lonely (+Attack, -Defence)
- Draco Meteor
- Dragon Claw
- Flamethrower
- Earthquake
Fast and hitting from both sides of the spectrum. Nothing can really safely switch into this thing. Perhaps Gyarados can, but it still gets a hard hit from Draco Meteor.
I haven't done any defensive sets since I think that Salamence isn't that good as a wall. There are better walls out there. Salamence should be hitting hard, versatile, and leave every pokémon afraid for a massive hit.
Overall, Salamence is the same as before, attacking from both special and physical sides, hitting hard, having a wide move pool on both sides of the spectrum and having Intimidate to ease switching in. It gained Hone Claws so it can use Dragon Rush which hits harder than Dragon Claw, and it gained Dragon Tail to frustrate counters switching in, but overall it's still the same. It's still weak to Ice Beam and Stealth Rock so defensively it's also the same.
I guess it gained a bit of dragon competition but overall its competitors lack the wide movepool to effectively use both special and physical movesets, and I think that Dragonite is still its largest competitor as a versatile dragon in OU, and I'm pretty sure Salamence will continue to be a massive beast and a top contender in the environment. Outclassed by Rayquaza in Ubers but perhaps slightly too strong for OU.
I think that a lot of pokémon stayed pretty much the same in the generation shift. There haven't been that massive changes to the environment as before. When going to the 2nd gen, special stats were split, when going to the 3rd, abilities were added, and in the 4th, whether a move was special or physical was no longer decided by type, but in the 5th there hasn't really been such a massive change affecting almost everything.