Before running out and installing Windows XP on that brand new Mac of yours, you may want to check out this article over at Engadget, entitled Will XP melt your Mac?
Apparently, the current XP install doesn’t include a fan driver, so your Mac may get mighty hot!
UPDATE: After much debate on the subject, apparently the answer is no, XP will probably not melt your Mac. But you may still want to do some research if you plan on trying this. Good luck.
In the onmac wiki it says:
Fans have been verified to be working, but are generally only audible under heavy CPU load or when the CPU temperature gets very high. There have been some perceptions that XP is running hotter than Mac OS X, but measurements indicate that maximum case temperatures under XP are no greater than under Mac OS X. CPU frequency throttling is confirmed working on a MBP under XP. Installing the Intel Chipset drivers is recommended.
http://wiki.onmac.net/index.php/Drivers
What he said ^
This news should not spread any further as this is not the case.