steambox will target pcs not consoles. Valve is not entering the console environment.....yet.

That is all.

I think that the least affected of the Big 3 will be Nintendo.

I could see going to steambox. The real question is will valve make exclusives for the steambox? Portal 3? Half Life?

Yeah I dont see this being successful either way. I think Valve is wasting their resources and money doing this. Who knows I could be wrong but I think this is a horrible move by valve

Steambox will likely not affect any of the consoles.
Like I said, they are targeting PC's not consoles. I don't understand your response, Otaku. Nintendo, nor Sony, nor MS should be affected.
The idea is likely to create an alternative to the standard PC model, so that instead of buying a PC, you buy a steambox as a dedicated gaming machine. Vale does not (yet, at least) want to enter the console market.
"Why", you ask? Because steam is a PC platform with lots of keyboard and mouse games...games that aren't feasible on televisions. Steambox will use regular pc monitors, keyboards, and mice, and simply use the steam platform that already exists.

A well developed PC-gaming machine could  save PC gamers literally thousands of dollars.

I highly doubt that people will care for this for a few reasons.  1 it is running linux over Windows.  Bad move number 1.  You just marked yourself off over 100s of millions of buyers.  But that's ok, we are basing it around steam.   The problem with that is a lot of PC gamers build there own PCs rather than buy a PC built already.  That lost them another big piece of the market.  Then you have developers who we dont even know if they will be keen on developing for linux.  There goes another chunk of the market.  How will they be able to market this product to people when they are already set with what they have.  VERY LITTLE AMOUNT of people buy PCs only for gaming.  i built a gaming PC but I also use it for other things which is why windows comes in handy.  Hopefully they didnt invest too much in this though.  

1. They don't need windows.
2. Not really an argument about how they lost customers there.
3. They don't need devs to develop for linux, linux is just an OS that can be tailored to play games the way windows plays them.
4. Not a lot of people buy PCs only for gaming, that is true, but very many buy 400$ video cards, and a somewhat equivalent 300$ steambox will be a great alternative.

You basically say you disagree but don't give any reason or logic to why you think I'm wrong.

1. They don't need windows but it sure as hell hurts them.  Windows is around 85% of the market.  That won't change regardless if they don't like Windows 8.
2.  HUGE argument.  They are making this for money, not charity. They have hit about 2% of the market if that.  I still can't think of one reason to buy a steambox unless it is uber cheap.  Then it will be weak for standards of PC and you are once again still missing Windows.  
3. That may be right so i wont argue that.  
4. You don't know the price of Steamboxes yet.  So far the only one Ive heard of was the Xi3 which is $1000+ and PC gamers buy PCs for power.  If it is $300 I'm just going to assume that thing is weak.

Give me logical reasons why PC gamers will want a steambox?  Remember I am a PC gamer btw.  So why would I get rid of my gaming PC that I built for a steambox?  

Console gamers will stay on consoles.  And PC gamers will keep there PCs and continue to build there own.  Very few of these will actually get sold.  Very few of each console gamers and PC gamers will get a steambox off of the information that we know so far.

It's running Linux but someone from Steam already said it would be easy to install windows on it as it's really just a PC.  Shipping with Linux is to save money for people who will be happy with the Linux Library (Which is not crap, I'm actually moving to Linux myself soon).

Yes lot's of PC gamers build their own computers like I did, but if Steam can put out a powerful box for around $400-$500 (with their new rumored controller) that will also act as a low bar for PC system requierments then Steam could be onto something.  Of course not all developers will develop for Linux (yes games need to be ported, but don't worry it's easy), but enough will that it will soon be a completely viable platform.

I need to upgrade my PC hardware soon like many people do but don't want Windows 8, I could build another PC, or I could spend about the same money or less to get a PC (Steambox) that has a set of specs that games will be developed for, like console games are developed to a certain set of specs, increasing it's overall life span.

Linux is also very good for general applications.  Sure there is no Office or Photoshop but there are free options for linux that do basically the same things, and it's all open source so the software is well fleshed out.

"Hopefully they didn't invest much in this", what they've invested in so far is Big Picture & Linux support, both of which are already running live on Steam & have turned Steam into a more feature rich & compatable platform.  All they need to do is choose specs, manufacturers, put it together & sell it online like the Nexus is/was.

PS: Someone before you said that the Steambox is not for TV's, and will be for monitors and keyboards & mice.  To that person I say, look at Big Picture, it is a new mode Steam can run in that is designed for TV's and dual analog controllers and it supports a lot of the top games.