Dropping Rogues as a Shadow PriestFollow

Dropping rogues as a shadow priest is hard if they get the jump on you as you will usualy be killed very fast (bieng a squishy sucks >_<) However, if you get the drop on them, its a whole diffrent story. try to get at least 1 dot on em b/c if they vanish without a dot on ull be in trouble. Then mindflay em as they get close to slow their getting close to you. Next once they are almost in range to attack you fear em. While they are running dont mindflay as they will end up closer to you. hit em with a mindblast then drop SF and use Smite. when the fear is about to wear off, get back into SF and mindflay em again ( renew your dots so they are on him/her all the time) then Mindblast, Mindflay, and Shadow Word: Death em till they drop ( only use SW:D when they are low on health.) it uses alot of mana but it works.

Playing a rogue myself, I can tell you most rogues pop CoS as soon as the priest break loose from the stunlock to avoid Psychic scream. Otherwise, they'll save it for the dots. Your tactic requires a rogue that ebayed and is both a mouseturner and a clicker. He must also be afk and completely dumb.

Trinket out of one the stunlock early, Scream immediately, drop Pain and VT on them. Do not use anything else that has a cooldown - Plauge, VE, whatever.
As soon as they're out of Scream, they'll most likely CoS and come after you again. Survive for the duration by ensuring Shield and Inner Fire are up.

When CoS drops, get Pain, VE, Plauge, and hopefully VT on them. You can attempt to kite them a bit, but it rarely works against a good rogue - either you'll end up backstabbed or, more likely, Deadly Throw daze + Silenced. Just stand there and take it. If Martyrdom procs, use that to get off Flays, else sick with Blasts and refreshing Shield/Inner Fire/VT. If you get kicked, use the opportunity to refresh whatever needs refreshing, and if Martyrdom just proc'd, getting a Gheal off can be a great use of that downtime.
When Scream comes up again, use it immediately. If he's low on health, get off a Blast+Death combo to make sure he doesn't have time to heal up.

If you're ever at near-equal health while he's distracted (probably feared), use to opportunity to get Flash/PoM/Renew on yourself. Switching back into shadowform depends highly on his health level.

That's what I do, at least. Good rogues are one of the tougher fights for me, though. I usually rely on my rogue partner to do most of the damage if I'm fighting a rogue, while I keep them distracted >.>