I feel that decks designed to win on the first turn are incredibly over-hyped. In nearly all cases, such decks are extremely temperamental and require an unrealistically fortunate opening hand.
Manaless Ichorid runs this in torder to generate a 93% chance at Bazaar of Baghdad in the opening hand. Then wins on turn 3 or 4, with almost nothing able to respond fast enough.
Posted By:
Lithl
(3/6/2011 9:25:54 PM)
Very useful in decks that go for a first turn kill. On a side note though, I feel that decks designed to win on the first turn are incredibly over-hyped. In nearly all cases, such decks are extremely temperamental and require an unrealistically fortunate opening hand. Then, if they fail their first turn victory or even their second, their probability of winning further plummets, as they are not designed for a "regular game" involving creature combat. With all this in mind, this card does help one's potential for finding that early lethal combo.
Posted By:
AvatarOfHOE
(1/10/2011 5:26:46 PM)
If you don't see why this card is great, you aren't a Johnny. This is a godsend for combo decks. And no other card offers a similar ability.
Posted By:
GoblinNaysayer93
(6/15/2011 2:03:14 PM)
If you google there is a deck that's supposed to be the best there is and it uses serum powder. That deck is focused on an important card being in your draw hand.
Posted By:
Nathreet
(7/20/2010 12:16:20 PM)
So, it can give you a free mulligan, or thing your deck for a normal mulligan? I'ma fan.
Posted By:
Designer_Genes
(9/17/2009 11:47:37 AM)
This might be somewhat interesting with Pull from Eternity. Or even Mirror of Fate.
Get a bunch of cards that have an effect while in the graveyard like Bridge from Below, Haakon, Strongald Scourge or Incarnations like Anger or Wonder, and then hope for a Serum Powder in your opening hand.
It really bugs me that it costs 
to cast, though...
Apparently this card was planned to become a land, this would have made the card far more interesting.
Take a look at that Daily MTG article:
http://www.wizards.com/Magic/Magazine/Article.aspx?x=mtgcom/daily/as3
Posted By:
Mode
(7/3/2010 8:16:58 AM)
it makes your deck smaller. so if you get a initial hand of card you don't need for a game, just remove them from the game and you'll have a smaller deck. meaning you'll have a higher chance of drawing somthing usfull. if you figure out a way to returned exiled cards, it's even better.
...but I'd never run this.
Posted By:
medomai
(4/25/2010 12:36:19 PM)
An opening hand of serum powder and a Misthollow Griffin or two means you basically start the game with a smaller library and an 8th card waiting in exile.
Posted By:
roguepariah
(6/23/2012 9:57:32 PM)
@medomai
If there are cards you don't need in your deck in your hand, then you should probably remove those before playing with that deck |D
Posted By:
pepperoach
(6/3/2011 9:45:07 AM)
Don't forget about Riftsweeper, fellow combo maniacs. Those crazy Elf combo decks in Legacy can run a playset of Serum Powder and a couple Riftsweepers, so that if their win condition (Banefire / Grapeshot) gets exiled by Serum Powder, they can recover it.
...For those who are scratching their heads wondering "Banefire in a mono-green Elf deck, wtf?" -- the Storm-combo Elf deck uses Glimpse of Nature and Heritage Druid to play a ton of cheap Elves, then it starts doing crazy things with Wirewood Symbiote and Nettle Sentinel.
Posted By:
Salient
(8/15/2011 11:39:04 PM)