Should Apple license clones for markets Apple will never or is very unlikely ever enter.
Example:
ToughBooks
http://www.panasonic.com/business/toughbook/toughbook-products.asp
Tablets
http://www.axiotron.com/index.php?id=modbookpro
Industrial computers that require specially certified enclosures (there are a LOT of companies who would happily used anything other then Windows, but have no choice)
http://www.advantech.com/products/PPC-175T/mod_1-2K0JMB.aspx
(others?)
Example:
ToughBooks
http://www.panasonic.com/business/toughbook/toughbook-products.asp
Tablets
http://www.axiotron.com/index.php?id=modbookpro
Industrial computers that require specially certified enclosures (there are a LOT of companies who would happily used anything other then Windows, but have no choice)
http://www.advantech.com/products/PPC-175T/mod_1-2K0JMB.aspx

(others?)