True, but bad form for the school to break it--word gets around and the next crop of recruits may think twice about committing...schools now are more subtle: will tell a senior before signing day that he or she may want to reconsider attending because playing time looks dim.
Also, verbals are just something for the headlines. Essentially, the school is saying that they want you; however, certain criteria must be met before any actual commitment. GPA and SAT scores, for instance, must be of a certain level. As does the continued growth in ability on the field as well as endeavors off the field.