We've done it. We made the Computers context an OU instead of a CN, which allowed us to hang GPOs on it. Soon we will be moving it again and calling it 'unclaimed'. Our techs are supposed to pre-create objects before importing, but they don't always do it. Putting the not-pre-created computers into an OU named 'unclaimed' makes it pretty clear who is responsible for what computers... no one.
The one problem you'll run into is older software that assumes the presence of 'cn=computers' in your tree as the default location for stuff. This is happily becoming increasingly rare.