This was my main first complaint. I've since grown somewhat used to it, but I use NoLock simply because I hate the lockscreen that shows no information. May check out Flyscreen. NoLock is a little stubborn, but giving the trackpad a long hard push sometimes is the key.
Either way, the power button to unlock the screen is a terrible design choice. First, it is a terrible human factors design, terrible ease of use, since it requires constant hand maneuvering or multiple hands.
Secondly, if HTC was trying to prevent accidental screen activations, the power button is MUCH more likely to be accidentally bumped. It sits on the end of a thin edge, and sits proud, so it can be bumped by many things. The trackpad, however, is a small button that is recessed from the surface, so it takes a small, rigid object like a finger in a deliberate motion to actuate it.
There should have been an option to use this. There should have been an option to choose the screen lock delay, or disable it together. These features have been on other phones. Phones people make fun of (*looks at Storm*). I hope HTC patches this, but its unlikely. Our main hope is a dev that can make a solid, bug free app.