How long will Sony last? Will there be a PlayStation 4?

I have been thinking about this for the whole month of December, but it appears that my opinion is being cemented. I believe that Sony will exit the video game market in the same fashion as Sega with the Sega Dreamcast. Originally, I looked at the NPD Group's software sales. When a PS3 is sold, Sony loses about $50. To make up for this, Sony plans on making money through great software sales. Here were November 2008's sales numbers:

Hardware
1. Wii- 2.04 million
2. DS- 1.57 million
3. Xbox 360- 836,000
4. PSP- 421,000
5. PS3- 378,000
6. PS2- 206,000

Software
1. Gears of War 2- 1.56 million
2. Call of Duty: World at War (360)- 1.41 million
3. Wii Play- 796,000
4. Wii Fit- 697,000
5. Mario Kart Wii- 637,000
6. Call of Duty: World at War (PS3)- 597,000
7. Guitar Hero World Tour (Wii)- 475,000
8. Left 4 Dead (360)- 410,000
9. Resistance 2- 385,000
10. Wii Music- 297,000

NPD Group Source

Notice that the only two software titles PS3 has on this list sell a little over 900,000 copies for Sony. This is not enough to make up for the money lost for hardware sales. This is what fueled my opinion previously, but recently I found something else. On the Wall Street Journal website, they say that Sony helped produce a $400 million Cell processor chip with Toshiba and IBM. It turns out that an IBM representative Adam Bennett showed this amazing chip to Microsoft which Microsoft used to make its Xbox 360. This allowed Microsoft to get the chip for the Xbox 360 before Sony could get the chip for the PS3, which was the primary cause for Microsoft's early release and PS3's continuous delays.

This does show that Microsoft, truly, could not have been successful without Sony. There is much speculation as to whether or not this makes the Xbox 360 a bad console because of this. In my opinion, it should not affect Microsoft very much. However, this situation could make Sony much more cautious about how they want to go about making a PS4, and will it scare Sony from making a PS4 if they don't want to go through the stress of making the PS3? The NPD Group numbers are a point that will simply be a positive for Sony to withdraw from the video game market.