I did ran into the some problem on suse-linux. attached you will find a patch which works for me on the tagged version tags/wagon-1.0-beta-1/wagon-providers/wagon-ssh, but the patch is for the trunk.
I do not understand the whole consequence of the patch, but it is related to the comment in the jsch mailinglist. for me it is very important to get this to work in order to introduce maven2 as build system in our company.
another thing here is that I have to run
maven deploy -B
otherwise the interactive-flag is set and that will always prompt for the password !!
than I put <interactiveMode/> into my setting.xml and surprisingly maven deploy work without prompt ! for me that xml-tag should better be called <batchMode/>, but maybe I understand something wrong.
hope that helps to get a working version.