Wait for someone else to confirm on the htc, but nothing changed on my droidx. I just had superuser privs. All of the "this app quit working" is when people flash custom roms. You don't do that when you just root. But you have to be rooted in order to do things like that. Lol.
Rooting gives you the power to do that if you want to.
When I rooted my droidx, I did it just so I could have the power to do other things if I wanted. I am still on factory rom. But I am able to get to parts of the phone that are off limits if I wasnt rooted. I made it where I could tether, later I got rid of bloatware, etc.