May I mention
http://www.recons.org/
"The purpose of RECONS (REsearch Consortium On Nearby Stars) is to understand the nature of the Sun's nearest stellar neighbors, both individually and as a population. Our primary goals are to discover "missing" members of the stellar sample within 10 parsecs (32.6 light years), and to characterize all stars and their environments within that distance limit." etc etc...
And, by extrapolation, improve estimates of population beyond this 'thoroughly known space'...
Their next Solar Neighborhood (TSN) Series report (#46) should appear soon...
FWIW, whatever the source, I'm hoping for better data on tau Ceti 'f', a sub-neptunian-ish / super-earth in habitable zone. At present, orbital plane error-bars put an uncomfortably wide range on mass and probable composition...