The official Twitter account for Cats tweeted the film's first trailer would be released on Friday.
"This musical is timeless," Swift says among footage of the set and the cast rehearsing dance numbers. "We got to update it in ways that I think are just so, so great."
"This film is an event," Hudson says.
Cats is an adaptation of the Andrew Lloyd Webber musical of the same name which is based on author T.S. Eliot's book, Old Possum's Book of Practical Cats. The film is set to arrive in theaters on Dec. 20.