Not seen such a code placement. Better keep __init_.py empty and move code to another file, say console.py (following Trac core naming convetions) or similar. You can preserve current way of component activation by keeping a single line in __init__.py like so:
from nukeuserplugin.console import *
Thanks. I haven't used trac in a while though, so i'm unlikely to do this. if you're interested in the plugin feel free to fork it, take ownership, whatever you like.