The autoblocker was designed for a purpose, and it still largely serves that purpose. I don't think there's a need to completely shut it off. However, they really shouldn't be affecting logged-in users, and I think that as UC says, having them only affect account creation and anon editing would be a wise move.

If you do this, then all a vandal has to do is create a whole load of accounts prior to his spree; block one and he will just switch to another.

I'd like to make an alterative suggestion: a sysop-operated whitelist. Any username on the whitelist would be immune from IP blocks (though NOT from direct blocks on the username itself).

There would be no need to pro-actively add users to it; all that would be required is to wait until a problem arises for someone, then fix it for them when they email to complain...

The beauty of this system would be that no logged-in user would ever have to suffer an IP block due to someone else's misbehaviour more than once.