2. Yes, of course. The words causing the ban to sunset could be modified or removed from the existing law, or another new law could be passed to "take over" from the sunsetting law, or an even worse version could be passed. Many laws have built-in expiration dates, but are regularly renewed. The makeup of Congress following the November, 200[b]2[/b] elections will be key to any continuation or replacement of the law.
3. Your guess is as good as anyones.
NOTE: many states have established their own copy of the Federal ban, but these will not expire. The PRK, for example, as a perma-ban in place.