It is called Source Code Pro and it is open sourced from Adobe. It s a great monospace font that works great on hi-res displays (as well as low-res). I find it great for code work or anything with color on black like the Terminal console or Sublime 2. This is the best font for Macbook Retina displays.
In the terminal, it is super sharp.
I particularly like the Light version which is a much thinner, yet still legible typeface.
At 10 or 11 pt, it works great on dark and light backgrounds.
These screenshots don't do it any justice. I suggest you try it out for yourself. I've installed it on all my Macs and Linux machines. For Linux, I simply put it in my ~/.fonts directory.
Sublime 2, TextEdit, TextWrangler, GEdit, Bluefish, they all look good.