There was an article in the NY Times a few weeks ago about a national ID card, which mentioned that the historical record is very clear that licensing of drivers and automobiles has never really been about safety. The real purposes have always been identification and tax collection, safety is just a pretext (and a thin one at that).

Bicycles are taxed at point of purchase, and identification is not much of an issue with cyclists as it's generally difficult for cyclists to outrun law enforcement. So no, there's no need for additional licensing.