Eigen 3.1.0-beta1 has been released on June 6, 2012.
This beta release introduces an incomplete LU preconditioner with dual thresholding, and an interface to the parallel PaStiX sparse solver (LLT, LDLT, LU). This release also includes the renaming of the SimplicialLLt and SimplicialLDLt classes to SimplicialLLT and SimplicialLDLT. Sparse-dense products have been slightly accelerated, while the support for permutation and self-adjoint view with sparse matrices has been significantly improved. This release also includes many bug fixes.
The final release of the 3.1.0 version is planed for the Thursday 21th of June.