It has been my experience as well that the Raptor drives do run a bit warmer than other drives. (For me I have only used Seagate, IBM, Western Digital, and (2) Maxtors for the last five years.)
Most of the Raptor hard drives I have installed are in Servers. I have a couple in PC's.
In the Servers there is no noticeable difference, to the touch or measured, in drive case temperature. The Servers that I use have a plethora of fans though and really good airflow.
On the two PC's that have Raptors installed they are DEFINATELY warmer. On those particular PC's I did not add any additional fans. (The stock fans are used which are a CPU fan, case fan, and power supply fan.)
On the PC's I have been running the Ratpors 24/7 on one, daily on another, since the 74gb ones came out. I haven't experienced any problems.
They are indeed running warmer that I would want them to, but I am considering them as a test for right now.
The rated operating temperature is up to 131 degrees Fahrenheit. So that would be pretty toasty to the touch. Mine are running more like 115 degrees Fahrenheit in the PC's.
The ONLY Raptor failure I have had, so far, has been on 74gb drive. That one was DOA. None have failed in use. (I have been using 36gb Raptors since availability, and 74gb Raptors the same.)