Some thoughts on the new speed mechanic when Mega evolving:
* Mega-Diancie, Absol, Beedrill, Lopunny, Sceptile, Aerodactyl, Alakazam, Gardevoir and Gallade, Houndoom, Tyranitar, Scizor, Metagross become immediately better. I'm very afraid of Diancie and Metagross being banworthy in OU with these changes because now can use immediately that good Spe saving a moveslot for Protect or HP.
Gallade has something new to distinguish itself from Medicham and Lopunny: it is way faster than the former in turn 1, but hits harder than the latter. Gardevoir, Scizor and Tyranitar are marginally better and now can wallbreak a little more easily. The same stands for Sceptile, which already has 120 base Spe in its regular form and this buff doesn't really help it over Serperior.
Lopunny and Alakazam, while already good before, are even better now. I won't keep to play Fake Out on Jolly Lopunny, though, because now the bunny can run two elemental punches at the same time, thus lowering the number of its checks.
* Garchomp-Mega becomes really, really worse than the regular form despite having 100 base-stats points more. Probably BL because it is too much for the UU tier, but useless in OU. The same happens for Abomasnow and, sadly, for Heracross.
* Maybe Absol might be now OU material as an offensive Magic Bouncer. I say "might".
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Some thoughts about Pelipper.
I see quite well this thing with Drought alongside +10 SpA and STAB Hurricane.
This thing has even U-Turn + Defog (if necessary) despite the SR weakness.
A simple set can be this:
Pelipper @ Damp Rock
Ability: Keen Eye
EVs: 248 HP / 252 Def / 8 SpA
Bold Nature
- Hurricane/Defog
- Scald/Defog
- U-turn
- Roost
Knock Off is also an option if you really want an utility move.