Was it balanced? No.
Was it fun? Hell yeah.
Back than if you wanted to raid, you had to spec holy/disc hybrid (21/28/0 or whatever the spec back then was, can't remember). If you wanted to pvp, you specced shadow, and you melted faces. The legendary "shadow priests melt faces in pvp" thread is a showing of our power back then.
Then came along the burning crusade...
Sorry couldn't resist. Anyway with the burning crusade suddenly everyone and their pet wanted shadow priests in raids. But with resilience our pvp power wained. Especially when they changed resilience to affect dots too, shadow priests were pretty much destroyed in pvp.
Now with Lich King things haven't changed for the better. We get a skill that reads pretty much "if you would die, you will now die 6 seconds later and have full mana, yay!". That's it.
Is that balanced? Hell no.
Is that fun? Hell no.
My priest was my main all through vanilla wow. With the BC I changed mains to my rogue. Now with Lich King I'm back to the priest again, because while rogues take names in pvp, I didn't really like being a cookie cutter all eggs in one basket class. Priests can / could do so much more. And I always loved the idea of a (especially undead) shadow priest.
I really hope things get better once we aquire a goog chunk of resilience. Also an interesting idea I've read on the US boards: Hybrid disc/shadow spec with shadow power and reflective shield. Something like this:
http://talent.mmo-champion.com/?prie...h=000000000000
Reflective shield is awsome with a disc spec, and I really think that a build like this could work for shadow too. Besides a few deep talents (and psychic horror which is really nice) all the good shadow talents are taken, together with all the shield talents. Gonna try that out for sure sooner or later.