Destro, is it viable in PvE?

[afhald]

if you are playing the warlock for fun and you aren't in a semi-hardcore guild, destruction spec is what you can use without problems; but if you want to top dps meters forget it and play affly/demo.

[Gnomelock]

If most of your raids DPS are destruction warlocks you can still kill the bosses!

It is about playing the game correctly