Why no Welder?
Without Welder in the deck, I cut all the expensive artifacts. I wasn't hard casting Smokestack, what made me think that Duplicant and Titan were gonna cut it? When I added the powerful coloured spells to the maindeck, the power of Welder went down proportionally. When I cut Tangle Wire, I cut the number of Welders down to two, but I realised that they and the expensive artifacts were ruining the consistency of the deck. The overall synergies within the deck increased as soon as I cut Welder and his chums. After cutting Welder, I began to see Kevin Cron's reasoning for cutting Welder. I was suitably inspired by his list as well: http://www.starcitygames.com/php/news/article/10203.html

No Smokestack.
See Ray Robilliard's thread: http://www.themanadrain.com/index.php?topic=28988.0
When I originally read Robilliard's thread, I thought that he was crazy. Wasn't the deck named after the card? However after games in which I was consciously keeping track of Smoky's effect on the game, I realized Ray was onto something. The format has sped up to the point where the turns required to charge up Smoky just to get your opponent to sac his worst permanent were far too precious. I won't say no more on this subject. Please read what has already been said in Ray Robilliard's thread

On Workshop vs Tomb
I originally had 4 Tombs and 1 Workshop, when I cut Welder, I found that I wasn't running enough artifacts to make Workshop useful, and just cut the last one. The original premise for replacing Workshop with Tomb was that Tomb could be used for powering out artifacts AND powerful non-artifact lock pieces. That is still true for the most part, and for a while I had only 4 Tombs and 0 Workshops. However, as Abdullah and many of the astute will notice immediately with playing a manabase containing Tombs and Cities is that the damage adds up really quickly. I solved this problem by replacing the Barbarian Ring with a 4th Gemstone Mine, cutting the 4th Tomb, and added 2 Workshops back in. Then I added more artifacts to make Workshop worth it, most notably Chalice.

But if damage is such a problem, then why Confidant?
The Confidants might bring up question marks, but I've just found them to be a fantastic addition, I think 3 is the right number, mainly because the damage in this deck adds up. They ensure that you can keep the pressure on your opponent, plus they put a clock on your opponent.

Why so few artifacts?
The reasons are many. For one, combo decks already pack a couple of mass artifact bouncers like Hurkyl's Recall; reducing the number of artifacts, and varying the type of permanents you play gives you greater resiliency against this. The reduction in number of artifacts is also a side effect of cutting Welder (see above). The second reason is the mana base. Abdullah's list runs 3 Workshops in addition to 4 Tombs, I think this is right if you are running a high number of artifacts, but that reduces the consistency with which you can cast your coloured spells.

The long forgotten power of Null Rod
For a while, Null Rod was recognized as the most powerful mana hoser in the format. However, recent developments have seen Null Rod fall out of favor because of the speed of the format. The primary abuser of Null Rod, Fish, could only cast Null Rod on turn 2 at the fastest. The format has developed to the point where decks that are vulnerable to Null Rod could deal with it if it came down later than turn 2. At a time when many had forgotten, Vroman came along and reminded the Vintage community what it feels like to be broken by the Rod. http://www.themanadrain.com/index.php?topic=25734.0.

// Disruption
4 [card]Smokestack[/card]
4 [card]Leyline of the Void[/card]
3/4 [card]Tangle Wire[/card]
4 Crucible of Worlds
4 Chalice of the Void
3/4 [card]Sphere of Resistance[/card]
// Creatures
4 [card]Gathan Raiders[/card]
4 Aven Mindcensor
// Other
3 Bazaar of Baghdad
2 Engineered Explosives
// Mana
1 Sol Ring
1 Black Lotus
1 Mox Sapphire
1 Mox Ruby
1 Mox Pearl
1 Mox Jet
1 Mox Emerald
1 [card]Horizon Canopy[/card]
1 [card]Cabal Pit[/card]
4 Scrubland
2 [card]Riftstone Portal[/card]
3 Ancient Tomb
3 Mishra's Workshop
2 Wasteland
1 Strip Mine

4 Sphere of Resistance
4 Chalice of the Void
3 Smokestack
3 Crucible of Worlds
1 Trinisphere

2 Engineered Explosives

4 Dark Confidant
3 [card]Juggernaut[/card]
2 Aven Mindcencor
2 [card]Jotun Grunt[/card]

1 Demonic Tutor
1 Vampiric Tutor
1 [card]Enlightened Tutor[/card]
1 Balance
1 [card]Darkblast[/card]
1 Bazaar of Baghdad

1 Sol Ring
1 Black Lotus
1 Mox Emerald
1 Mox Jet
1 Mox Pearl
1 Mox Ruby
1 Mox Sapphire
1 [card]Lotus Petal[/card]
4 Mishra's Workshop
1 Swamp
1 Plains
1 Bloodstained Mire
1 Flooded Strand
4 Scrubland
1 [card]Urborg, Tomb of Yawgmoth[/card]
3 Wasteland
1 Strip Mine
1 Tolarian Academy