Our first public release of the new iATS Payments extension for civicrm is now ready.
I've just created the extension node on civicrm, here: http://civicrm.org/extensions/iats-payments
And I've published the code over on github, here: https://github.com/adixon/ca.civicrm.iats
I think that means you can now just enable it within your CiviCRM install via the extensions mechanism (version 4.2.9 and above).
Anyone using a non-Drupal CiviCRM that needs this is especially encouraged to try it out.
Note that only one-off payments are fully supported in this release. The recurring contribution code is set up, but needs some additional work as per: http://forum.civicrm.org/index.php/topic,29449.0.html