By popular demand, I decided to take a look at the HtcDialer.apk today to see how easy it might be to disable haptic feedback while dialing a number. Turns out, it was a 5 minute job
Should work on both the latest DC and Fresh 2.1 ROMs.
Flash the attached signed zip if you prefer to disable the haptic feedback "feature". Always Nandroid before flashing. It could bork your system, but it seems to be working fine for me. YMMV.
No Haptic Feedback Dialer
Note: This will change you back to the stock dialer format.
EDIT: Here is a no haptic feedback dialer with black buttons