Pay what you want for The Humble Introversion Bundle with Uplink, Darwinia, DEFCON and Multiwinia. Pay more than the average to get Aquaria and Crayon Physics Deluxe as well. Steam codes are included.

Meanwhile, Indie Royale's Really Big Bundle is available for preorder at $3.99. The games aren't yet public, but the title is stated to be a hint so I'm guessing Really Big Sky will be included. Desura sponsors Indie Royale so expect codes for their service. (I have not seen Desura codes for Humble this time around. Battle lines!)
The Really Big Bundle currently includes Really Big Sky, Runespell: Overture, Cthulhu Saves the World, Eufloria and Breath of Death VII. Both Desura and Steam keys are available. As I type this, the minimum price is a little over four dollars.

Really Big Sky is yummy.