It is possible.... here is how!
I first realized how much I wanted to remap keys after I used a cyanogen rom a while back. He had an option that would allow you to let the power key end a call when pressed. This was awesome because I hate ending calls by touching the screen because sometimes I press it twice and accidentally redial and so on... Anyway, I've switched to a million different roms since and this option is not present on any of them. I knew there was a way but figured it was far too difficult. It isn't...
I followed the tutorial from the hero forums using the link in the first post. The file that you need to edit is in the same place that the hero file is in but it's called supersonic-keypad.kl instead. I edited it right on my phone using root explorer... But I'm sure you can use other methods. For my simple edit I changed the second line. I deleted the word power and replaced it with ENDCALL
... I recommend reading the tutorial carefully and making a copy of the file before making any changes just incase. I am going to remap a couple other things now... But that was my main concern. After editing it... Save and then reboot your phone to let the changes take effect...
I hope this helps!