On Apple's full size USB keyboards you have a separate delete and backspace key. Both still called delete, but they do the same task as on other machines.
As for rebooting, that is slowly going away, only for major updates that modify libraries that may currently be in use by applications is it still required, mainly to be sure that those apps start using the updated version rather than keeping the old one around. With Lion's support for going back to a previous state upon logging in that has become almost seamless, my windows are back in the same location after a reboot as they were before the reboot.
As for rebooting, that is slowly going away, only for major updates that modify libraries that may currently be in use by applications is it still required, mainly to be sure that those apps start using the updated version rather than keeping the old one around. With Lion's support for going back to a previous state upon logging in that has become almost seamless, my windows are back in the same location after a reboot as they were before the reboot.