If a 3-D Shrek title sounds familiar, you may remember the short film shown at Universal Studios and then released on DVD a few years back (even before Shrek 2 came out.) The IMDb actually labels the thing as Shrek 4-D, but I'm pretty sure the video is titled Shrek 3-D. Of course, it was made before the current Real D 3-D technology was being utilized (it still used the red and blue glasses.) Actually, if you follow all the trends closely, you may even remember that the first Shrek was supposed to be shown on IMAX in digital 3-D (again, the old kind.)
The fact that the 3-D plans for the original Shrek fell through and the fact that 3-D technology is now suddenly different are both likely reasons why DreamWorks didn't want to convert its movies to the format sooner. There is currently great support for Real D's production and projection tools, but it will still be awhile before enough theaters are equipped with the projection equipment to make for widespread appreciation. The studio's CEO, Jeffrey Katzenberg says there was interest in releasing 3-D versions of the studio's 2007 and 2008 releases (which include Bee Movie and Madagascar 2 in addition to Shrek the Third), but he wanted to only release films in 3-D that were produced with the format in mind.
The first movie DreamWorks Animation will release in 3-D is Monsters Vs. Aliens, which looks like it will be an homage to Asian monster movies. The movie will open exclusively in 3-D in the summer of 2009, when 3-D projection equipment is expected to be set up on a few thousand screens in the U.S (especially now that Dolby has made the transition cheaper for cinemas). DreamWorks apparently doesn't think 3-D-enabled home entertainment systems will be so popular yet, because the movie is also being produced in 2-D for its DVD and television release.