UPDATE: More Robert Downey Jr. on 'Iron Man 4'

UPDATE: Robert Downey Jr. continues with his big Iron Tease. The actor appeared on The Late Show With David Letterman Tuesday night and seemed to reconsider his previous stance, saying there is no plans or script for Iron Man 4 despite some persistent prodding from Letterman. He did say, “There’ll be other stuff.” When Letterman asked him again, “Are you going to do another Iron Man?” Downey answered, “Just between us — no. But I’m going to do other stuff with Marvel…. There’s going to be plenty of fun stuff to happen.”

Iron Man fans who’ve been desperate for signs of a fourth movie in the Marvel series got the answer they’ve been looking for today. Robert Downey Jr. confirmed that Iron Man 4 is indeed on the way.

The revelation came during Downey’s appearance on The Ellen DeGeneres Show on Tuesday when the host asked the actor, “Will there be a fourth Iron Man?” Downey ultimately answered, “Yes,” to an audience who was so surprised that they took a moment to applaud their approval.

See the video below:

That wasn’t the only news the Iron Man actor dropped today. (He’s starring in the drama The Judge that hits theaters Oct. 10.) He also participated in a Reddit AMA live chat and had lots to say about Mel Gibson, Perry Mason, and his other big franchise, Sherlock 3.

Sherlock Holmes 3 is happening.

“Yes, we have a Sherlock 3 in development,” wrote Downey Jr. on the Reddit message board. “We want it to be the best of the series, so that’s a pretty tall order.”

He might not have been serious about having Mel Gibson to direct the next Iron Man, but he still wants to work with the Braveheart star.

When asked about his recent remark that he’d only do another Iron Man movie if Mel Gibson directs, Downey called it an “offhanded remark.” But, he does have plans to work with Gibson, saying, “I have other projects in mind for Mel and I.” Then more cryptically he added, “sooner than later the Marvel Roster will be made public and all questions will be answered.” We think that means stay tuned.

He could show up on S.H.I.E.L.D. one day.

"Nothing is impossible,” wrote Downey about a possible appearance on the ABC Marvel show The Agents of S.H.I.E.L.D. “But there might be a fair amount of red tape involved in something like that.” Later, when a fan asked on what T.V. show he’d most like to do a cameo, he answered — naturally — Agents of S.H.I.E.L.D.

He’s still looking to get Perry Mason on the docket.

“Perry Mason is a property I’m looking forward to developing further, going back to the 1931 book series,” Downey said of the fictional legal eagle, “similarly to what we did with the first two Sherlocks, mining the original material for things that are ‘new.’” He went on to say the project, in development, “is kind of a pre-Chinatown gumshoe thriller with some courtroom stakes, and action sequences.”