Here's Patrick Chapin explaining how awesome Survival of the Fittest is. It's true. I don't know what the designers were exactly thinking, letting you discard a creature card to get any other creature card in your deck. Other colors have to draw cards, or tutor for maybe 1 card at a time.
Let's talk about zero casting cost creatures. Ornithopter was the first one. Shield Sphere was another one. Phyrexian Walker is yet another. Chapin found one I've never really thought about.
Future Sight can probably by considered the 3rd Un-set, considering how much weird stuff it contains. Dryad Arbor is a "man land," similar to Mishra's Factory and Treetop Village. Except it totally fails in the areas most people look for in their creature-lands. It's always a creature, and lacks all of the creature-destruction evasion stuff Mutavault is known for.
But it turns out, there are some benefits to having both card types for the long haul. Listening to the video, Chapin likes that you can pitch Dryad Arbor to Survival of the Fittest. He also enjoys putting the Arbor into play with Aether Vial. Does anyone know the keyboard combination for Æ by the way?
Really, anything that has to do with creatures, lands, or creatures AND lands. Life from the Loam brings Dryad Arbors back into your hand. Proclamation of Rebirth brings Dryad Arbors back onto the battlefield.
When another creature enters the battlefield, Intruder Alarm causes Dryad Arbor to untap.
There's all sorts of ideas. I'll keep thinking about it.