Guess who’s there again? Check out the International Journal of Astrobiology’s Highlights of 2010 for free. While my entry is obviously worth your attention (and you can find a blog post about it here), there are plenty of others to check out too – including an early discussion of arsenic as a potential biochemical substitute (well before the NASA press release madness of last December).
The 2nd Law of Thermodynamics (whether you understand it or not) governs much of what happens in the universe. Could it be responsible for sentience? Some recent work by a collaborator of mine suggests it as a possibility.