UPDATE: miRBase version 19 is the current version
Yesterday the latest miRBase Version 17 was released and judging by the numbers this is a rather significant update. This latest release of the microrna database contains 16772 entries representing hairpin precursor miRNAs, expressing 19724 mature miRNA products, in 153 species. There are 1626 new hairpin sequences and 2406 novel mature miR and miR* products that have been added.
Surprising to me personally is the large number of new human miRNA sequences: The number of known unique mature human miRNAs increased by 521 (or 43%) to the current count of 1733 (up from 1212). While only a single new mature rat miRNA is included, there are now 71 new mature mouse miRNA sequences listed in the database. Apart from the additions and corrections there are also more deep sequencing data added.
As usual, the data are freely available to all through the web interface at http://www.mirbase.org/ and in flat file form from ftp://mirbase.org/pub/mirbase/.