sinnix

It's a trade-off.  The DVD drive would be quieter if it was slowed down, but that would effect load times and you'd see mandatory installs like on the PS3.  The fall ultra-update's new copy to hdd feature will largely resolve this issue though (if you want to splurge on the over priced 120GB hdd).

It's also important to note that if your 360 isn't in a well ventilated area the cooling fans will spin faster and as a result create more noise.