That is correct, there will be both Shrek 4 and Shrek 5 films. Shrek Goes Fourth, as the movie is titled, is currently in preproduction for its expected May 21st, 2010 release. According to Dreamworks co-founder Jeffrey Katzenberg, Shrek Goes Fourth “will come back to understand how Shrek arrived in that swamp. We will reveal his story.” The main cast members including Mike Myers, Eddie Murphy, Cameron Diaz, Julie Andrews and Antonio Banderas are all expected to return for Shrek Goes Fourth as well as Shrek 5.
Jeffrey Katzenberg confirmed that there will also be a fifth Shrek movie. Both of these upcoming Shrek movies will be released in both 2-D and IMAX 3-D. Shrek 5 is expected to be released on May 24, 2013.