Two points:
First, IMHO they should stick to the original planned conversion date. Seems to me they have spent plenty of time and money informing people about the situation and what they need to do and helping finance conversion boxes. In the end there will always be some people who can't or won't cope well even when warned and assisted in the process. Some people will only act after they lose the signal. IMO if they haven't caught on after a years worth of saturation bombardment then odds are they won't. And, white frankly, I'm sick of all the public service announcements on this subject.
Second, anyone getting a conversion box might find it advantageous to buy on with a 'pass-through' feature. This allows analog signals to go through the digital conversion box. This allows you to see analog shows on stations that are still broadcasting them before the time limit.
After the conversion date there are some markets where low powered analog broadcasters will be allowed to operate. These will likely be educational, local school training transmitters and pubic access type channels. If the conversion box lacks analog pass-through you will have to either buy a separate switch or manually disconnect the box and connect the TV to the source to get the analog signal.