Many people note that 2008 is so far away that without an excellent crystal ball, nobody could predict what the update will contain. But one thing I reckon for certain about Longhorn is that it will be able to run Linux software.
Such a move would provide Microsoft with some excellent ammunition to win business from companies looking to deploy Linux, and those looking to replace Unix-based Risc systems with Unix based-x86 ones. If Microsoft wants to sell more server software, adding this capability to Windows would be a fine way of doing it.
Link: VNUNet.com