So, I played for a little bit last night and a creeper apparently spawned and then exploded (as I obliviously walked passed) quite close to the indoor glass encased lava fountain I had built in a sub-basement of my house. So, I spent the next hour doing damage control trying to keep lava away from my chests and building tables. I managed to die only once due to lava damage, but I lost two of my dogs to it.
Right now, I'm thinking that I have either the option of playing on survival mode and not building any remotely extravagant structures in the lower levels of my house or playing on creative mode and missing out on the fun of killing zombies and being watchful for creepers.
Bah, maybe I'll just one world devoted to creative mode and another for survival. Either way I'm definately removing that lava fountain.