I've had this game a few months, and playing multiplayer hasn't ever crossed my mind. I'd really like to find a server to play on! SSP has its perks, but after awhile being out in the empty vastness all by yourself gets a bit boring.
I really like the idea of the "minecraft sprinkler system". Putting water between the roof and ceiling would probably quell any fires started by lightning.
I hope the next update to minecraft gives us more crafting recipes... I'm running out of things to create!