Current Status of mixnets for voting
I found a few for shuffles.
The papers below will be good pointers for recent results.


Stephanie Bayer and Jens Groth: Efficient Zero-Knowledge Argument for Correctness of a Shuffle. EUROCRYPT 2012.
Melissa Chase and Markulf Kohlweiss and Anna Lysyanskaya and Sarah Meiklejohn: Verifiable Elections That Scale for Free. PKC 2013.
Melissa Chase and Markulf Kohlweiss and Anna Lysyanskaya and Sarah Meiklejohn: Succinct Malleable NIZKs and an Application to Compact Shuffles. TCC 2013.