Terminator is a pretty good example. The Sarah Connor Chronicles basically ignored T3 and rebooted off of T2. Terminator: Salvation then went back to T3.
But it doesn't really matter if it's been done before or not. All that matters is if something is viable. And personally, I don't think there's much difference between the old universe, the Abrams universe, and just doing a new reboot altogether. As long as they tell good stories with good characters, people will watch.