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.
Windows On Theory 
Why is SIGACT news behind the ACM pay wall?
Good question. I’d be happy to add an open-access link to SIGACT News article. Meanwhile, here’s a link to Mikkel’s pre-print version.
This is the default for ACM-published materials. As a SIGACT member you can log in to read it without charge even if your institution does not subscribe.
SIGACT News is a volunteer effort magazine and should be treated as such and should be widely available to any one interested (not just SIGACT members) instead of treating it as a formal publication hidden behind the ACM pay wall. This is my opinion.
I sympathize with this point of view. In some sense everything our community publishes is a “volunteer effort”. In addition to the volunteer part, I think that SIGACT News actually costs more to produce than the SIGACT member dues so I also see why ACM would want to recoup costs. SIGACT News has been both a news publication and as well as having original research papers (e.g., P-completeness of the Circuit-Value Problem) and original research syntheses that appear regularly in many of the columns. It may be worth considering alternative modes of running SIGACT News in which it more resembles a news feed or in which it is augmented by a news feed.
My guess is that the costs have to do with paper production and distribution. Maybe we should simply get rid of that.