How do I translate the Webform module form?
The Webform front-facing form was given the ability to be modified (and thus translated) in this issue: Make Webform multilingual (i18n) aware through contributed modules. That enhancement is already included in the latest versions of Webform, but that improvement is merely at the API-level; Webform module doesn't provide any translation abilities itself.

The add-on module that provides translation abilities for Webform is called Webform Localization, but it is currently only available as a sandbox project here: http://drupal.org/sandbox/GDrupal/1407100

The author of the module just recently (2 weeks ago) received the green-light to turn the module into a normal fully-promoted project, which will make it more easily accessible on Drupal.org.

The Webform Localization module provides two modes of translation, one that uses separate nodes and syncs certain webform settings between the nodes; and one that uses a single node and makes the strings available to translate through the i18n_strings module. The single-node approach is also what I've been advocating and I've tested that it works with this module. Only the single-node approach keeps all of the results from all languages aggregated together, with separate nodes the results are separate for each language.