Now it looks like we have something in the way of official confirmation, as it's been revealed by TheHollywoodNews.com that former SNL staffer and Austin Powers screenwriter Michael McCullers has been tapped to pen the screenplay. McCuller's previous credits include Austin Powers: The Spy Who Shagged Me, Goldmember, and also directed and wrote the hugely underrated Baby Mama that starred Tina Fey and Amy Poehler.
No director has been attached yet and it's unclear if Eddie Murphy, Cameron Diaz, Justin Timberlake or Antonio Banderas are signed on to reprise their respective roles, but it seems unlikely that they can make a Shrek film without Mike Myers.
The last Shrek film, Shrek Forever After, was released in 2010 and had a disappointing run at the US Box Office, making $238 million. It did, however, make huge gains internationally - close to $514 million - and it's that very reason why Shrek 5 is happening.
No release date has been set, however it's been suggested that we'll see Shrek 5 some time in 2019.