"offensive" disc priest?

[Medically Insane]

I've never played a priest before, but they look very interesting to me. I took a look at their talent trees, and I saw "Atonement" at the Disc tree. So I thought that I'd make a priest and play offensive disc in PVP. Is that viable? Power word shield + great heals + heal when you do damage with smite and holy fire looks like an awesome class for me.
or should i just play shadow in pvp?

[Oneirophobia]

It kind of plays like a shockadin used to way back in BC, sept not as bursty (You used to run in, hit your ...what was it called, divine touch or something, and garuntee your crit with holy shock, then put out your wings with avenging wrath and shock. Generally floored someone. Used to do 2v2 with a PoM Pyro mage, instant pyro and a buffed shock = one of their players dead off the bat.) You're gunna want to heal as much as possible, and when you're sure your allies can handel themselves, then start smiting and just heal via attonement.

If you're really geared, you can smite+attonement your way through heroic dungeons. Its actually pretty fun. End of wrath I was doing this in heroic ICC gear and out DPSing people in boss fights.
With Power Infusion you can smite extremely fast so you can put out a fair amount of DPS in a pinch.

Is it REALLY that viable though? Not really, you're still going to be healing much better than damaging, but is it fun? Yes, very.

Its also very unexpected, so you'll have a lot of try-hards coming at you to pick on you that you can kick to the curb. Thats always my fav part. ;3

Also, I used to hope that one day they'd make that tree like the feral druid tree and allow you to heal or DPS as disc. Being a holy caster dps is more appealing to me then a ret paladin for some reason.

[Yilar]

If you want to be "offensive" in pvp go shadow. While you can still be offensive as disc in comparison with other healers killing anyone with half a brain is almost impossible by yourself in cata.

Oh and attonement is beyond useless in pvp, ignore that shit. The range is bad and it heals for to little.

[Jubite]

PvP Disc Burst is mindspike x3 -> Mindblast. If you wanna get fancy glyph into SWD to help when target falls in execute range.

Atonement is for shadow. Bliz just put it in the wrong tree.

[Alfredhitchcock]

I've never played a priest before, but they look very interesting to me. I took a look at their talent trees, and I saw "Atonement" at the Disc tree. So I thought that I'd make a priest and play offensive disc in PVP. Is that viable? Power word shield + great heals + heal when you do damage with smite and holy fire looks like an awesome class for me.
or should i just play shadow in pvp?

Disc Priests can be extremely offensive when used right in PvP, however Attonement is a waste of points for a few very good reasons. Firstly the range is awful, secondly you'll need to heal with instants far, far more than you will be able to with casts and finally, it heals for next to nothing.

The way to do offensive disc pvp is to spec like this (including glyphs). If you get the chance against a casting DPS, pop Power Infusion and spam mana burn like a madman, or if they're low and their mate is CCed, spam mind spike and mind blast then SW when below 25%. In that situation though I usually pre-cast mind control so the healer is cced for another 8 seconds, rather than risk going for a burst kill and the healer coming out in enough time to save the day.

Smite and Holy Fire should -never- be cast in arenas for one big reason and one small. The big reason is that if you cast smite or holy fire and they get interrupted, then you're locked out of your healing spells. This won't happen if you get interrupted casting mind spike / blast as they're shadow spells. The small reason is they just don't do the damage comparably.

If you want to play offensive then Spriests are great, but healing wise disc priests are so much fun to play in arenas! Their versatility is awesome, and to me spriests just felt like when dispersion is on CD that you can't survive without heavy, heavy peeling from team-mates.