Dave,
You're question here, https://groups.google.com/d/msg/bigbluebutton-dev/50___TQ8MVI/aSU3XH59-4EJ, ties in together with this one so I'm just going to put a longer answer here.
Currently the presenter and any moderators can't vote on a poll, instead they see the Stats Window. So in that sense the final results are hidden from viewers. We ran into an issue though with the polling module and recordings. People wanted to know the results of a poll when they played back a meeting. The solution that was chosen was to generate chat messages from the results finished polls. This way any one viewing a recording can recall what was polled and what happened.
So if you want to hide the results from viewers you can, but you'll lose any recording capability. To disable the chat message you just have to comment out the contents of the method messageForRecording found here, https://github.com/capilkey/bigbluebutton/blob/poll-access/bigbluebutton-client/src/org/bigbluebutton/modules/polling/views/PollingStatsWindow.mxml#L161.