The Amsterdam Cinema Expo has been turning up several treats recently, the latest of which is another poster for Terminator Salvation: The Future Begins. You can see the banner, which shows a terminator with gun-arm attachment (a type we don't recall from previous movies, but we could be wrong) at Filmonic here.
The fact that it's hanging next to the banner for Keanu Reeves-starring sci-fi remake The Day The Earth Stood Still, which you can see better at Film1.nl here, pretty much confirms this is genuine.
Thanks to reader Joe for the tip.