It has been stated over at IMDB that Harry Potter and the Goblet of Fire, the fourth film in the series, is now in post-production.

Post-production is what happens when filming is near or has reached completion. During this time the effects are added and the film is edited.

This would fit with earlier reports that stated that filming for 'Goblet of Fire' would finish sometime between February and April, of this year.

However, as this is IMDB saying this and not WB, we should still be wary.

Source: Harry Potter Fan Zone