In electronics it is often happens when one model retires and another one takes its place. Some stores keep the pages of discontinued products for google hits. But there is no good automated system to route users to the new model.
It would be cool if we could specify a model then the cart would 301 to or would display a certain banner explaining that this item is no longer current and a user should proceed to a specified link to see the new model.
You can vote to add this feature in the Ideas forum:
[url]http://cscart.uservoice.com/forums/40782-general/suggestions/703038-discontinued-product-redirect-to-current-product[/url]
Bob