My palm purchases go back to 2000!
Mine, too! Fortunately I downloaded everything when B&N bought them. I'm actually surprised it's taken them this long to close - thought it would be sooner.
I copied a list of all my books from my bookshelf just to be sure of what I have. That was tedious - Gah! 57 pages.
You can also use the bulk download, which makes it a little less painful.