um....I'll respectfully disagree on that one.
0/41/30 felguard w' emberstorm.
http://www.wowhead.com/?talent=IZ0xIzsgMq0sxzZVchVrzuV
You can swap 1 or 2 points from demo tactics into fel synergy if your healers suck but you really shouldn't have to. The FG is far more durable than the imp and scales w' all the melee buffs. A shifted imp is an option when you can't have feltard out.
The direlock build isn't bad its just the imp is still pretty frail. Also w' the 20% attack power felguard glyph (10% now) in next patch expect FG builds to gain 100'ish dps over what they do now or 200'ish over non glyphed.
Best way is to try both on test dummies switching glyphs (imp vs felguard) and running some instances. You will want glyph of immolate, possibly CoA (small dps boost but gives more uptime and 2x more ticks to help MC procs), and glyph of felguard/imp.
Deep destro will also gain during the patch but its a bit more gear dependent.
One other spec that gets little press but does alot of dps early is
http://www.wowhead.com/?talent=IfxMbzMAoVq0IstcxM0cZV You have all the goodies of affliction w' the boost of demo aegis. You lose ruin but if your crit is low (which is the case early in gearing) its more dps than about anything.