As announced in the Drupal 6 extended support policy, 3 months after Drupal 8 comes out, Drupal 6 will be end-of-life (EOL).

On February 24th 2016, Drupal 6 will reach end of life and no longer be supported.
What this means for you:

Drupal 6 will no longer be supported by the community at large. The community at large will no longer be creating new projects, fixing bugs in existing projects, writing documentation, etc. around Drupal 6.
There will be no more core commits on Drupal 6.x to the official tree. (see What if I have a Drupal 6 site still)
The security team will no longer provide support or Security Advisories for Drupal 6
All Drupal 6 releases on project pages will be flagged as not supported.
At some point in the future update status may stop working for Drupal 6 sites.

More info:

https://www.drupal.org/drupal-6-eol