Yeah the lack of hardware buttons/switches is going to be the hardest thing for me to adapt to. With my current htc device, even though the touch screen works fine, I always use the hardware buttons to launch the browser, launch the mail app, pull up the dialer, end a call, switch to roaming only mode with a long press, pull up a task/app launcher, scroll pages with the volume wheel, turn on the led flashlight with a long press, turn off the screen only without going to sleep mode, pull up the camera, rotate the screen, turn on/off wifi, etc etc... And that's all without sliding out the hard keyboard or touching the screen.
I think the popularity of the iphone is responsible for htc making the move towards devices with minimal hardware buttons/switches, because before the iphone they loved em. I do wish they had one line of sleek stylish phones like the evo, and another line for geeks that want to be able to customize tons of buttons to do tons of things directly. But I'm not complaining: the evo is awesome, I'm happy with their design, and I will get used to using it.