I like the idea of adding elements to keep the game "fresh" that dont necessarily effect gameplay.
Ideas like themed bacgrounds, night/day or even updates for seasonal changes or similar seem like a cheap easy way to do this that other games have figured out long ago, but still elude SC. (They were only years late to the party on offering value packs/ specials.)
I would also like the glacier theme. I feel like I mentioned something like this in someone else's thread a week or two ago, good to see a well formed thread about it!