Here's an interesting read courtesy of kotaku.  Nikkei electronics took apart a couple of xbox 360's and measured the temperature as well as looked at the design of the heatsink and placement.  They also looked at a repaired xbox to look for changes.

http://techon.nikkeibp.co.jp/english/NEWS_EN/20070801/137224/ 

Highlights:

"When designing consumer products, it is common to seek a temperature gap of around 10°C between exhaust and room temperatures," the thermal design expert said. "The 22°C is quite a large gap, in the first place."

The cooler fan's maximum wind speed was 1.1 m/s, only 1/2 to 1/3 compared with general desktop PCs. It may be partly because the fan rotation was reduced to lower noise. According to an expert's analysis, "The amount of switched air is slightly in short considering the chassis' size (309 x 258 x 83 mm3)."

  "The heat sink on the graphics LSI is so small, I wonder if it can really cool down the board," our expert said.

In the Xbox 360, however, the duct was cut off before the heat sink and the DVD drive, and, instead, chassis took up the heat sink's upper area probably due to limited space inside the chassis.

Do we really need proof from some outside source to tell us that it was rushed to the market and designed poorly?

In only five minutes since we started playing the game, the temperature of the heat sink on the graphics LSI rose to 70°C. The thermal gradient was about 10°C/min.

In 15 minutes, the microprocessor heat sink temperature stabilized at 58°C, but the heat sink on the graphics LSI rose to 80°C, 57°C above the room temperature.

Assuming room temperature of 35°C in mid-summer, the gap is estimated to reach more than 90°C. In that case, the temperature of chips in the graphics LSI could exceed 100°C.

Jesus Christ... now, that just... sucks.

I have yet to see any GPU on any of the computers I've had go over 90°C.

Sweet, my 360 can brew coffee now. They should print that on the box as a feature.

That could be a great selling slogan.

360, so hot it makes you tea!!!!

LOL

Microsoft should take the marketing strategies as Sony and market the 360 not only has a gaming system but a coffee brewer/bacon griller/small apartment heater.

 You may not but others may find interest in what temperatures the 360 could go and see what design choices they made that caused all the red rings.  

 seriously man.  why is the ps3 the system thats called the grill anyways?  its the 360 that barbeque stuff.

is it me or is it funny that any japanese related company would look at the 360?  

Its called a grill because some people modded a PS3 case into an actual working grill. 

http://www.techeblog.com/index.php/tech-gadget/playstation-3-grill