4 duress
4 hymn of tourach
1 mind twist
4 pernicious deed
4 nantuko shade
4 tempting wurms
4 withered wretch
1 unearth
3 skeletal scrying
1 necropotence
1 demonic tutor
1 vampiric tutor
4 dark rit
1 black lotus
1 mox jet
8 swamps
4 bayou
4 bloodstained mire
4 wasteland
1 strip mine
sideboard
3 moment's peace
3 naturalize
3 bind
3 trinisphere
3 seedtime
What you basically have here is a non-optimal suicide black with Deeds and the Wurms. The Wurms are great on the surface, I mean a 5/5 for

{G} is awesome, but you only have a moderate amount of discard. To analyze it;
4x Duress: Cannot hit creatures or lands, therefore probably more useful for pulling a counter than a threat.
4x Hymn to Tourach: Good, but

{B} means so second turn Wurm usually.
1x Mind Twist: Barring a double Ritual hand or whatnot, never really effective early.
You are not very likely to pull what you need gone, as only 5 of them can even hit creatures, and those are random.
There are just too many cards that your opponent can drop that would totally destroy you. With no maindeck kill (and none of the SB, except for artifacts) other than Deed, all your opponent has to do is drop Platinum Angel, Exalted Angel, Psychatog, Masticore, Morphling, Pentavus, Triskelion, etc. (and don't say "Nobody plays Morphling, yo!!!" because I know that, I'm just using an example) and you're dead.
Pernicious Deed itself seems a rather odd choice as the only kill in the deck. Sure you can blow up a threat they pitch in from the Wurm, but you'll most likely lose the Wurm then! It's an interesting deck idea, and the Wurm thing has been floating around for a while, but I don't see your deck having optimal matches anywhere.
Against Dragon: All you have is a bit of discard and the Wretchs.
Mask-Nought(in its many shapes and forms): You have less kill than they have Duress/Unmask. And 12/12s tend to own 5/5s. A lot.
Slaver: You just die, they're faster and stronger. I hear Tempting Wurm isn't that good when your opponent plays it for you.
Fish/Landstill: Probably a bit of a better matchup, but they'll just counter the Wurm and Deed, and the rest of the match is theirs. Shade and Wretch are fine, but owned by Fire. And manlands get around Deed and Duress, meaning you're quite heavily screwed. Also Standstill resolved makes Wurm a whole hell of a lot worse.
Hulk: They match your discard, counter your threats, Deed/Smother/Whatever your Wurm, drop the Tog and it's game. They also out draw you by miles.
In summary, I don't really think the deck in and of itself is viable. If you seriously think I'm wrong and it's great, feel free to hit me up on AIM (HunterKiller403) and I'll be happy to take you with whatever on Apprentice.
-Dan