I've had the 600 patch for about three months now, and part of that time was with the 800 also....Umm... because the hardware was not designed to run that fast. That's why Palm has LunaSysManager set to run at 500 MHz and 600 MHz in games.
Even running at 600 MHz day-in and day-out was said to cause the chips to have an average expected lifespan of 30 days or so. I can only imagine how long it'll take more people to fry their phones at 800 MHz. But of course, anything's possible... and all your Pres will run at 800 MHz until the end of time...
If you want NO problems, you shouldn't even be using Preware and other homebrew... but at least that can only possibly cause "significant damage" to the software. Only a patch like this that tweaks the hardware can possibly damage the phone for good.
You, my good sir, are against all that is good for Pre. Without homebrew, the Pre would have failed.