The news from the Cornelia Funke website is that the first tailer for Inkheart will be shown at the Cannes Film Festival.
She told me that it is absolutely fantastic!
AND - today (14 May) she left for London, because Iain Softley will show her the complete first cut of Inkheart.
Once they show it there, we should see it soon. I recall the first look at Fellowship of the Ring was at Cannes.