Here is some good news for 'Iron Man' movie franchise. Director Shane Black has recently confirmed that the fourth installment of the hugely successful series from Marvel Studios is happening and Robert Downey Jr. will be reprising his role as Tony Stark.

Quoting Master Herald, IB Times reports that even as speculations were rife about Downey's return as Stark, Black was cent percent certain that Downey would be the man to don the Iron Man suit again and that 'Iron Man 4' will get rolling soon.

According to the website, 'Iron Man 4' has been delayed as the production house was engaged in negotiations with the actor, who sought an increase in his already high talent fee - $50 million. The report further stated that Marvel was likely to agree to the actor's price, considering the fact that 'Iron Man 3' was a huge success for the studio. The film earned $1.22 billion at the box office.

While it finally appears that Robert Downey Jr. will be back for the fourth installment, there are several other plot and cast rumors that have made the fans really curious.

According to one such "wild" rumor, Harley Kenner (Ty Simpkins), the boy genius who met Tony Stark in 'Iron Man 3' and helped him capture the Mandarin, will replace Downey Jr. to don the superhero's suit.

Movie News Guide reports that Tony would retire after 'Iron Man 4,' which may possibly be set in future where Harley will be an adult and to be ready to succeed Dawney Jr. In addition, the website indicated that the change in 'Iron Man 4' casting may also be a build up to the future films.

According to another rumor, 'Iron Man 4' may release after 'Marvel Phase 3' in 2019. Some reports even speculated that the extended Marvel Cinematic Universe may come to an end after 'Phase 3.'

The most important rumor suggests that the plot of 'Iron Man 4' may perhaps revolve around the terrorist organisation Ten Rings - the reason why the Iron Man suit was created.

Which of these rumors will turn out to be true will be known only when Marvel Studios release an official statement or after 'Iron Man 4' hits theaters. Till then, fans of Robert Downey Jr. can get their RDJ fix with 'Captain America: Civil War,' which is scheduled for release on May 6, 2016.