What are some common themes of steampunk fiction? (If you have suggestions, please comment!)

I’m thinking along these lines:

Punk, to me, at base means rebellion against an establishment.

Because steampunk is influenced by the culture of Victorian England, I also feel there needs to be some kind of commentary on colonialism and empires, and on class divides. Looking at these issues through a “real world” lens is an important part of this.

Technology versus nature also ought to be in there, though on the whole I feel technology in steampunk is usually favorable so long as it’s wielded by the good guys. Tech might be temporarily bad, but I don’t think I’ve ever seen anything steampunk in which technology ended up being abolished. If it causes bad effects, they’re usually outweighed by the good.

Thoughts? Comments?

Here’s an interesting related post at the Age of Steam blog: The Darker Side of Steampunk.