So you want Sony, Nintendo, and Microsoft to come together and create one console or you want each of them to make the same console?

As Nintendownsmii said, the price of a single system would likely be much larger than anything on the market today. There'd be no reason to get involved in the hardware if your software can reach everyone at someone else's expense, which means the hardware will have to turn a profit as well.

I really think that a unified format will improve everything, not just one console.

The point here is that manufacturers should be able to create their own versions of the same format.

It would be better for the consumers and the developers. No ports, no different codes.

I think that many publishers want this, because for them is extremely expensive to develop games for 3 different consoles.

With unified format and the end of physical storage, the cost of production and manufacturing a game will decrease significantly.

Your looking for something like the 3DO? While it would be a different outcome if the big 3 tried something similar, given the failure the 3DO was, I can't really see any console company wanting to jump on the bandwagon any time soon.

http://en.wikipedia.org/wiki/3DO_Interactive_Multiplayer

i was giving an example of what a unified system would look like. Let's put a little more imagination into this -- what would happen if we had a Nintendo Wii but with the graphical horsepower of the PS3 and Blu-Ray and the online would use Microsoft's Xbox Live? And all at around a $400 SKU?

And if Hi Def wasn't your thing, the games would include a 480p mode and a $250 SKU which would have the horsepower of the current Wii, but would maintain the Xbox live stuff?

Nintendoownsmii, if the price of the console gets too expensive, then consumers will go ahead and buy a cheaper version made by a different company. Its much like if you saw a Sony DVD player for 200 dollars and a Toshiba one for 150, then you would get the Toshiba one if you thought the Sony one was too expensive.

Anyways, there would be many different generic variants of the same console-- perhaps EA would have their own version or Konomi would have theirs -- much like how HP, Dell, and Gateway all run Windows, but they have their own different brands and niches.

In the end, it should benefit the consumers and if they consumers spend more money on games and not having to buy 3 different consoles, then the game makers would all benefit!

Here's an excerpt from the 3DO article:

By the early 1990s, the video game market had become overcrowded with a plethora of consoles. Sega, Nintendo, Commodore, SNK, and Atari each had a video game system on the market. When viewed internationally, the chief competition for the 3DO during its peak had been Nintendo's SNES, the Sega Genesis and NEC's TurboGrafx-16 platforms. The higher quality of later CD-ROM based systems that emerged in the mid-90s (primarily the Sony PlayStation), the limited library of titles, lack of third-party support, and a refusal to reduce pricing until almost the end of the product's life cycle were among the many issues that led to 3DO's demise.

For a significant period of the product's life cycle, 3DO's official stance on pricing was that the 3DO was not a video game console, rather a high-end audio-visual system and was priced accordingly, so no price adjustment was needed. Price drops announced in February 1996 were perceived in the industry to be an effort to improve market penetration before the release of the promised successor of 3DO, the M2. Heavy promotional efforts on the YTV variety show It's Alive and a stream of hinted product expandability supported that idea; however, the M2 project was eventually scrapped altogether.

The second paragraph sounds eerily PS3-ish.

Anyways, it was the fact that the console market was OVERCROWDED, i.e. disunified and 3rd party developers had pick and choose where they wanted to develop their games.

Guess the size of the market determines the number of players - microsoft really warmed things up but theres plenty of room for three next-gen's ,legacy ps2's , and portable devices ,as well as PC's , basically any console which sells over 10million worldwide is a good target platform for developers to write software for.
X360 has it made very strong in the US now , the Wii is astronomical evrywhere, and the PS3 is on target for 10Mil in a month or 2.
Between the 3 there is not much room for improvement ( 1080p, motion , networking take your pick ) so it would be really tough for a new console right now to offer anything the others dont allready have.