I have just figured out a way to do something I have had many requests for over the years but always thought it was impossible, or at least too cumbersome and difficult to be worth the effort.  
 
Once a Sales Order has been entered, we will soon have the ability to track changes so that there will be a record of the original order and any subsequent changes to quantity, price, Customer Due Date or Estimated Ship Date by line item as well as any new line items added or original lines deleted.  In the SO-A line item screen there will be an Order History button that will display the history of changes to that line.  
 
I also envision the same drill down in the SO-I Customer Service Inquiry when inquiring on a SO line, some new reports of Changes to Orders and the ability to include changes in the Bookings Report (SA-A) so that a true net bookings for a reporting period can be presented, including changes to previously booked orders.
 
I know this is an ISO related issue for many users, please provide feedback as to anything I may be missing here.  And yes, I am already anticipating the desire for a similar tracking of changes to Purchase Orders....   One thing at a time.

Yes.
 
Another one would be item rev. levels

This would be really cool if it could be applied to BOM changes also.

Excellent update idea.

Yes Yes,
We have need to print the original acknowledgement many times after shipments.      Somewhat similar to  
original Purchase Orders.

Amen.  This would be great.  Go for it, Lynn!