Unless enough people don't update, then we'll just end up with two forks. Yay... more DRK forking in the near future.
So there are options to stop that.
Enforce, checkpoint to get everyone on the same fork, remove enforce.
I don't see the issue. A fork is natural any time a major block proof revision occurs... The only thing that makes it a problem is when people refuse to update and you end up with more wrong fork than correct fork.
Think about is... Why is enforce off on RC3? Baiting... Most everyone is on .5 or .6 now, right? It has Pimp Hand in it, right? So, when RC4 comes out, Pimp Hand is enabled on .5 and .6 so even those who refuse to upgrade will be on correct fork... The only people on wrong fork will be those who deliberately downgrade to a much older client... These people will then be identified as obvious, deliberate saboteurs.