Pursuit can also be an option over either Poison Jab or X-Scissor.
The idea of this set is to predict a powerful hit (most of which are when used against a Pokemon as frail as 'drill) and use Endure to hit 1HP. The tier that Beedrill is played in will help it - there are rarely SStorm and Hail teams in UU and NU, so sitting on 1HP isn't too awful. Getting down that low will activate Salac, allowing you to sweep with Endeavour. Sort of. Beedrill's choices are pretty slim, so your best bet is bringing something bulky down to 1HP, getting killed by it, and then bringing in a revenge killer to finish it off (Dugtrio?) Your two STAB moves are pretty cool, but you may want to go with Pursuit so you're not stuck against Ghost types.
Jolly can work over Adamant...
Predict a hit that you can survive (read: nothing in OU), use Swords Dance, activate your Berry and attempt to sweep away with your Swarm-Boosted X-Scissor. Go with Brick Break if you're terrified of Steels, but it's probably reccomended you just switch out to something more adept at handling those Defence-laden critters.
Please note that Swords Dance can work as well over Agility, but you have no guarantee of Out-Speeding your opponent to the Baton Pass the next time if you do so.
The options for the last slot are; Roost / Subsitute / Swords Dance / Agility / Sunny Day / Poison Jab. Sunny Day works best to stop Sandstorm ruining Focus Sash's fun.
First things first, you cannot have this set without having Pokemon XD; this is the only way Beedrill learns Baton Pass. Now then, it's up to you whether or not you choose to pass Speed or Attack; I'd recommend Speed as you'll want to be able to outspeed the opposition to use Baton Pass, providing you're at 1HP. If you're fancying your chances, you can run both Agility and Swords Dance, and hope that their starter will switch out to something they know can easily OHKO it; allowing you to get one boost in. They attack, you survive with 1HP, you use the other boost, and then Baton Pass next turn to something that'll be able to resist the move. It's risky but can work wonders. As for his attacking move, remember that Swarm'll kick in at 1HP and can give you a good attacking offence. However, the only flaw in using two boosts is that everything can damage/OHKO Beedrill so it's unlikely he'll get the chance to use another boost.
Sunny Day's a weird move on this set, but it allows you to neutralise Sandstorm / Hail on your first go if something like Tyranitar stares in your face, but it's circumstational. Really, the top three moves are the ones Beedrill'll use 99.9% of the time, so the fourth move doesn't matter too much really.
Choice Bee Holding Choice Band Ability: Swarm Nature: Jolly EVs: 6 HP /252 Attack /252 Speed Moves:
ChoiceScarf/Adamant or ChoiceBand/Jolly works.
Choice Beedrill is an odd bee, but can work well in UU/NU. X-Scizzor and Poison Jab are for STAB. Pursuit is cool, since now Beedrill can hit any running Psychics or Grass types. Aerial Ace is to hit other UU Bug types, and some Grass types thast stay in. Brick Break, on the other hand, can hit Dark/ Rock/ Steel/ Normal types, and Steel is a notable type, as it resists all Beedrill's other attacks.