Because we didn't know they could do it. I hadn't really heard anything about it until they announced the date for the change. The only thing I'd heard was third hand about five years before with no details of what they were proposing or the consumer equipment to support it.

Yes, it was specified by law. The law also specified that >85% of the population had to have access to cable or satellite reception before the date for switchover was set. IIRC even after that they delayed it at least once.

As far as HD goes, I want anything I can get in it.