What has happened in the meantime is anyone's guess. It is hard to imagine a more capable film-maker than Baz Luhrmann to transform the Great American Novel to glorious 21st century high-definition technicolour, so the delay can only be speculated upon. There has been talk of clashing release dates in the past. May 10 seems like a fairly reliable one to put in your diary.
There's a nice Vanity Fair piece on the mansion here