I hope they rebuild. I can't imagine it will be quite the same, but it's wonderful to see people from all over rally support for such a beautiful piece of history.
A handful of French megarich have already pledged more than 600 million Euros (~675M USD) for the restoration. I don't think money is going to be an issue. However, the destruction was extensive and we have yet to learn whether what remains is structurally sound. The largest stained glass windows, which gave the interior its magical light--have survived, fortunately. But it will certainly take years to recover. I recall just happening to visit once while an all Bach organ recital was in progress, which was phenomenal good luck. The organ has been damaged, apparently, but I don't know how badly.