Greg I've always had a tough time with Shakespeare. I can imagine the actor on stage winking at those men in the audience who are balding or who are wigged. Then again, you know the story about how there is another author involved, so Shakespeare may be poking fun at the other author.
Casey Peterson I believe it's to get at the main theme of communication or rather the difficulties people have with getting across even simple or plain meanings through speech. The twins and doubles of everything in this play are supposed to illustrate how even the same word can come across completely different to two people, more specifically the one person saying the word and the second person hearing it. Baldness also ties in with father time and how much time is wasted in flowery speech when something so simple is meant. Another link (cause Shakespeare finds a million) exists between baldness and venereal diseases that cause the loss of hair. These diseases spread quickly like misinterpretations from speech especially when one person isn't being faithful/honest and will inevitably share this corruption with their significant other as when Adriana believes her husband is being unfaithful.
Tom Well it is Shakespeare and that leads itself irrevocably to over-analysis. Here's a thought (no doubt to be scorned by the armchair Shakespeare scholars): maybe it was intended to simply be witty word-play for the amusement of the audience. Crazy idea, right? But then again (as the saying goes), sometimes the simplest answer tends to be the correct one.