@rodbegbie, you’re totally right.
We’re going to start by implementing this as an option for new-style RT’s only.
And I think if the users don’t choose to filter them, we will still change the construction for Facebook (e.g. change it from “RT @username: message….” to “…message /via Real Name”
We will leave conventional RTs (i.e. regular tweets leading with the construction “RT @username”) unchanged.
How does that sound to people?
Users are asking us to try to filter 'new-style' retweets. However, the Twitter API gives us those in the form of 'old-style' ones (e.g. "RT @username: ..."). So, the option would be to filter out all tweets that contain this construction.
How do people feel about that?
This issue is slightly complicated because TweetPo.st just sends the link to Facebook, which then crawls the page and automatically chooses the first image it finds on the page for the preview.
It is possible (and very simple) for the service to optimize their pages so that the right image is selected by Facebook for the preview (see http://www.facebook.com/share_partners.php). We have submitted a Get Satisfaction request for TwitPic to add this support: http://getsatisfaction.com/twitpic/topics/optimize_twitpic_pages_for_facebook_sharing. So, please go vote for it.
Update It looks like the folks over at TwitPic have acknowledged the issue and are going to work on it. They have promised to update http://getsatisfaction.com/twitpic/topics/optimize_twitpic_pages_for_facebook_sharing when it is done.
Another one for this would be 'HT' to 'Hat-tip'.