Something interesting...

I've noticed that as well. You can no longer hard power off. If the machine is frozen the power button is completely nonfunctional. Odd, normally power buttons effect hardware first, and software second.

I also noticed that the machines now enter clamshell mode gracefully. Normally, you'd plug in a monitor, and power, close the lid, wait for it to go to sleep, then wake it back up.

This meant if your macbook was charging and asleep and then you plugged in a monitor, you could wake it from sleep straight into clamshell mode. I tried this in lion and it resulted in this non responsive power button situation. I had to wait for the battery to run down.

Now, if you connect a monitor while it's awake, and close the lid, it goes straight to clamshell without going to sleep. Kinda slick.