I like this tip, thanks, but I can't seem to get the new terminal based application to accept a new icon by pasting it into the inspector.

Anyone had better luck ?

So here's what I did...
I don't know if you have to use an alias or not, but this got me a custom dock icon:

1. Make an Alias of your "app.term"
2. Rename it to what you want it to say when you mouse over it in the Dock
3. Copy and paste your desired icon to the alias
4. Drag the alias to the dock (in the file/folders section near the trash)

Note: The icon will still not show up in the finder, but WILL show up in the Dock. Dunno how it works, but it does.

Hmmm...
First time I've rebooted in days (love OSX)...
Those icons don't seem to stay on the dock "app.term" icons after a reboot. Must have something to do with the dock. Like the way the "pin" and "orientation" attributes don't remain. I wonder if saved terminals have the same type of properties...

Ah well, if anyone can figure out a way to make any of these things more permanent, I'll bet we'd all be happy.

over and out.