Eigen 3.3-beta2 has been released on July 26, 2016.
The source archive is at: http://bitbucket.org/eigen/eigen/get/3.3-beta2.tar.bz2
Since the previous 3.3-beta1 release, this beta version received more than 1000 commits including numerous fixes, some performance and numerical robustness improvements, as well as some key novel features such as the new CompleteOrthogonalDecomposition class for fast minimal norm solving, fast reciprocal condition number estimators in LU and Cholesky factorizations, support for inplace decompositions, unaligned vectorization, support for the new ZVector SIMD engine, support for any BLAS/LAPACK libraries as backend, improved support for mixing scalar types, and more.
The new performance comparison table of dense solvers might also be of particular interest to help you picking the right solver.
If you missed the major novelties introduced in the 3.3-alpha1 and 3.3-beta1 releases, check the page dedicated to the 3.3 release for a comprehensive review of all the novelties and improvements introduced in the 3.3 branch.
As for any beta release, everybody is highly encouraged to test this release on their own code and report any compilation issues or performance regressions on the bugtracker.