Open problems are of course very valuable for setting research directions and pointing out current or grand challenges. I would like to point out two more recent lists of open problems that are “closer to home” for me at least.
- sublinear.info is a wikified List of Open Problems in Sublinear Algorithms. This one is actually a few months old project that consolidated lists of open problems from several workshops in the area: IITK Workshop on Algorithms for Data Streams 2006, IITK Workshop on Algorithms for Processing Massive Data Sets 2009, Bertinoro Workshop on Sublinear Algorithms 2011, Dortmund Workshop on Algorithms for Data Streams 2012.
- SIGACT News just published “Mihai Pătrașcu: Obituary and Open Problems”, written by Mikkel Thorup. The article lists a few problems that Mihai and Mikkel deem important challenges in data structures.