Jon Favreau uses Twitter to drop a big casting announcement on us?

He sure seemed to do so, as you can see in this from The Hollywood Reporter:

Is Harrison Ford in "Cowboys and Aliens?"

Casting speculation has run rampant since Monday when Jon Favreau tweeted that he had some cool casting news coming down the pipe regarding the new movie he is directing for DreamWorks.

It was Latino Review that first speculated it was Ford who was joining the movie.

Today, Favreau tweeted “Please stop asking if Harrison Ford is in 'Cowboys & Aliens.' Okay? He is. Please don't tell anybody.”

While the tweet took DreamWorks execs as well as Ford’s agency by surprise, it isn’t the first time that Favreau, an avid tweeter, has gone rogue with his Twitter account. The director initially feverishly tweeted from the set of “Iron Man 2” and was told to reign it in.

Tom Hanks is another Hollywood-ite bypassing the media or publicity machine, recently tweeting casting updates for the dramedy he is directing, "Larry Crowne." Hanks sent out a picture of a wall of headshots, and later showed table readings with the actors. Publicists for some of the actors were none too happy to learn that some media outlets would not be covering their actors boarding the movie.

-And people say Twitter is useless...thoughts?