Last week, Dwayne Johnson, a.k.a. The Rock, posted a picture of himself on the first day of shooting for the upcoming sequel to 2009’s GI Joe: The Rise of Cobra, entitled GI Joe 2: Retaliation.

He’s now confirmed via his Twitter that Bruce Willis, who has recently been rumoured to have joined the cast for the second film, has officially boarded the project, and Johnson welcomes the fellow action titan with open arms.

“Welcome brother Bruce Willis to the cast of GI Joe! What an honor. #HeavyArtillery.”

Willis’ attachment to the project came as a bit of a surprise, given that the first film did well at the box office but not particularly well in terms of people’s reaction to it. However, it looks like things could well be different this time around, and with Zombieland’s writers, Rhett Reese and Paul Wernick, penning the script for Retaliation, I’m hopeful that the sequel will be a lot of fun to watch. Having Johnson and Willis join the cast certainly suggests there will be plenty of action to look forward to, coupled with the fact that its title is ‘Retaliation’.

Hours after welcoming Willis, Johnson followed his first tweet up with this, a clear Willis homage:

“Saturday. On set. GI Joe. 112 degrees. Puttin bullets in heads. #YippeeKayayMotherfu**er.”

He definitely sounds like he’s having fun with the filming, despite the temperature being intensely high. And just a few days into filming and the action sequences are already a-plenty, so we at least have some great visuals to look forward to in the sequel. With filming already underway, Paramount have their eye on a 29th June, 2012 release, so Retaliation will be one of their biggest summer blockbusters next year.