Holy fast responses! Friday morning I received a nice email from Chris, a pr guy for Grouse Mountain, outlining the reasons that the lights are on at night. With his kind permission, I've included the email below.

Aaron-

Here is why the lights of Grouse Mountain remain on until 2am every morning:

I remember hearing once that BC Hydro donates the electricity to Grouse because they consider the lights a tourist attraction. So not only is Grouse wasting the electricity & messing up our beautiful view at dusk, but they're also (if the rumours are true) doing it for free. Well, not free exactly, because we're paying for it!

The prospect of that makes me very upset. I guess I'd better verify the facts before I get too mad, though...