That setup Disc+ Rogue is one of the best in Current season :)
Rogues are.. hmm rogues :P Good in CC's quite nice burst dmg + mortal strike + few abilities to survive dmg on them :)
Disc priests are hmm best healers for them cause of few things.
1) Shields - rogues can be sometimes literally one shotted, and when they are out of Cd's they just take whole dmg.. and cause leather aint best armor ever spike dmg hurts.
2) Priest Can dispell shields from other target , e.g Sacred Shield is rogue worst nightmare, it stop most of his dmg, beacause for true Rogue is hitting not that hard but faster.. and Sacred Shield absorb some ammount of dmg from every each attack...those shields are not that devasting for Warrior/DK/Retries cause those classes are hitting HARD and slow, and ofcourse they can dispell also Rogue from some frezzes, snares, etc etc and your Rogue wont be forced to burn his Cloak of Shadow or Vanish to get rid of that
3) Priest are AMAZING dpsers; > that's true ,poing Power Infusion +2 dots+ Mind Blast + holy Fire+ Spam Smite (and smites can crit for like 3k :S ) It's amazing help for Rogue to get someone down :)
4) MANA BURN - it's for true the best spell (just right after Penance) for Disc Priest, it extremly fast devastate other healers mana, they are getting Oom in tomie if you will keep casting it on them.
Everytime when your rogue is stunning healer - Burn Him, everytime your rogue is doing such a big pressure on target so his healer need to keep spam healing him, BURN him, everytime you dont have anything better to do BURN healer :>
Of course fights wont be THAT fast.. it's still DPS + healer setup, so remeber to bring Water for arenas :>
And one more thing SHADOWFIEND is OFFENSIVE cd, not Defensive: > use it asap as your Rogue ask for it ;) And dps :> a lot of players can die in first burst dmg of you two :)
Few more tips.
ALWAYS shield your Rogue right after arena start, so he will be able to walk on D&D, or Consecration :)
If there are some Stealth in oposite team, stay next to your rogue and keep spamming Holy Nova, maybe you will be able to hit one them :> which will basicly win a fight :)
If your rouge manage to sap someone, Fear Him right After Sap is gone :> But remeber if there is a shaman in oposite team first just Destroy His Tremor Totem :>
Penance is best spell to heal :) So remeber to always use it firstly., But remebre it's CHANNEL spell. so it's really easy to interupt it,
So if you are being zerged and there is some Warrior/Rogue/DK on you. let Penance to Tick only 2 times and then just stop it :) Move or someting. a lot of Ppl will waste their interupt :>
Did I say about using Fear ? DO IT every CD :>
and Remeber to keep dispelling :) That's your really good weapon :) Dispell yourself, your partner, and oposite team :>