Taking into account user feedback, the policy will evolve in the coming weeks and months
Writing on its official Project Glass Google+ page, Google explained that because of privacy concerns it will not be approving Glassware (apps for Glass) that take advantage of facial recognition technology. While a consumer release of Glass may still be several months away, there are now enough people out there with Explorer Edition units that Google felt the need to address this concern. One of the biggest struggles it is fighting with Glass currently is concerns over privacy, and following its current company line on the use of facial recognition it thinks that now is not the time to include it.
Google says that it is listening to feedback from early users of Glass, and will be evolving its policy on facial recognition software in the coming weeks and months. We of course know that with a little bit of hacking non-approved Glassware including facial recognition could easily be added to Glass, but in these fragile stages of building public perception of the product it is best for Google to have an official stance here.
Source: +Project Glass