For institutions in which cross-platform environments were the norm they would generally have to build their entire file share technology around this limitation. Rather than having the ability to organize shares into logical units, or even include the ability for transparent fail over, only direct top level shares could be created (sometimes creating an unmanageable sea of directories). For those that chose to implement DFS irregardless of the Mac's ability it would usually then necessitate expensive licensing from add-on products such as Thursbys ADmitMac to provide the needed DFS capability.
After extensive testing here at Go Go we can safely say that 10.7 lion has support for DFS which should help ease the burden of enterprise storage administrators as they move forward. The man pages relating to the newly created SMB utilities in Lion also directly reference DFS. From the man page of 'smbutil':
Display the Dfs referrals for this URL for the authenticated session.
Great news indeed.