A rumour was reported yesterday about Uncharted perhaps making a showing at Sony Gamer's Day. The rumour originated from B3d forums, from the lead character artist.
This is just a rumour. And to put this into context, they do not know when there will be gameplay footage of Uncharted: Drake's Fortune, as this is all down to Sony's marketing. Richard Diament made this very clear in his posts, stating that although the marketing train had started for Uncharted, when or whether footage was to be shown is not in their hands.
Sony Gamer's Day was hinted at for exciting news on upcoming games from Sony, but whether there will be footage of Uncharted is unknown.
All we have for now is this trailer using the ingame engine in 2005.