I know I'm a few days late, but I liked these two design-related jokes:

• A Ford re-branding which was well balanced on the lame/professional line, enough so to believe that (horrifyingly) maybe it was true. In this case, it was a student's class project. Good PR for him.
• The Serif announced Helvetica Serif, based on drawings by Max Miedinger. The joke was poorly executed, though, since the sample shown is nothing more than Times Bold. In fact, Google coughs up an actual attempt at Helvetica Serif, which is at least different enough to have sparked some outraged reactions.

Some people think April Fools' jokes suck (though is that post itself a joke? hard to say). But I like them because the best ones work by exploring the edge of plausibility. They are witty "what if?" questions. Could Ford really have tossed out their century-old brand? Other companies have made moves that bold/stupid. When a joke like this works, it's because it's in the twilight zone between obvious and impossible.