NetWare 6.5 SP7 still supports installing NetWare directly to the server (not running on top of Linux).

Will future support packs continue to support this until General support for the product has ended in 2010 or will we be forced to install NetWare on top of Linux at some point if we want to continue using NetWare for awhile?

There is a plan in place to migrate to AD but it will most likely take up to 3 or 4 years.