Thoughtseize

[treezzzzz]

Thoughtseize
B
Sorcery 
Target player reveals his or her hand. Choose a nonland card from it. That player discards that card.
You lose 2 life.

I saw this in the Lorwyn spoiler and it seems like it could replace duress in most decks that currently run duresses cosidering that it can take creatures too at a measly cost of 2 life.  There seems to be a lot of creatures going around recently, so this could be pretty good (Quirion Dryad, Dark Confidant, etc). 
Does anyone else who knows more about the format think that this card could replace duresses?

[captreynolds]

I think that Thoughtseize will probably most likely be used in conjuction with Duress as it does almost the same thing, and could take up spots normally filled by counterspells.  As far as card advantage goes this is almost better than using a Force of Will, as it it one card instead of two and it can pick spells before they are cast and avoid counter wars with your opponent.  Effectively I think that Thoughtseize could alter the format of Vintage due to the fact that people who run four Duress now are going to find cards to cut to add in four Thoughtseize.  Even with the loss of life this card is amazing.  Most people who run Duress will probably pick up at least a couple for their decks.  I know I am already cracking a box to get at least one and will probably unload the rest of the box to get even more Thoughtseize!  I don't think it will replace Duress at all!!

[Shock Wave]

This card will see limited play and will certainly not replace Duress. First of all, it is vulnerable to Misdirection, which has become almost as prevalent as FoW in recent Vintage. Even though the caster of Thoughtseize retains control of the spell, they still have to choose a target if it is misdirected, making it a 2-2 trade. I'd much rather cast Duress on turn 1 and force my opponent into using their FoW or losing a key business spell.

I can see Thoughtseize making it into mono-black decks like Suicide, or even raw combo like The Contractor or Grim Long, but otherwise, I see it having splash impact at best.

[FlamingCloud]

I don't see what the problem with a 2 for 2 is.  The purpose of duress is to slow your opponet down or remove his own disruption.  Presumably a 2 for 2 would slow your opponent down more than a 1 for 1.

[Shock Wave]

I don't see what the problem with a 2 for 2 is.  The purpose of duress is to slow your opponet down or remove his own disruption.  Presumably a 2 for 2 would slow your opponent down more than a 1 for 1.

The problem isn't the fact that you're getting a 2 for 2. The problem is that you're not getting the card you want. With Duress, it either gets you a 2 for 1 deal, or it gets the card of your choice. That's a very significant advantage.

[Malhavoc]

..and if misdirected, it makes you show your hand to your opponent. Something that, particularly if you are playing combo, is not good at all.