Ignorant query about digital broadcasting

[flippyshark]

The cute animals thread was starting to drift into an interesting conversation about the new digital broadcasting standard, and I thought I'd put this here so the discussion had a home. Especially because I have a question about it, and some of you smart people might know. My question has two parts:

1) Once the analog channels are gone, will digital signals take over that part of the broadcast spectrum, or will that become "empty space?"

2) If the former analog part of the spectrum remains free and unused, would it be possible for enterprising amateurs with the proper equipment to produce pirate analog TV broadcasts? If so, I want in!