there is (as far as I found) one bug in the genericviews module. It's the deprecated ConfirmedFormAction() method call in line 114, called via $this->DeleteForm() in line 83 (genericviews/code/RecordController.php). Commenting out line 83 will at least prevent the module from crashing in 2.4rc1 ;-)
And besides the functionality to delete, everything else worked fine again. This no fix, but a workaround.
I've replaced it with a normal FormAction for now, r104600. Fixed another bug in unit tests, but that should be it for 2.4 compatibility (all unit tests pass). Let me know if you have any further trouble.