I think AvPvT could be great, if it were done just right. I think the downfall of the existing version lay in its post A:R setting. It left both the predators and terminators feeling too tacked-on. I think the only setting which would really work well for this scenario would be the Terminator near-future. The Skynet defence grid could shoot down a passing predator craft, recognising it as an opportunity to develop technology which could allow it to leave earth and spread to other worlds. In the meantime some of the human refugees have come across the wreckage and stumbled upon a cargo of alien eggs, with the usual results. Of course the surviving predator(s) would be none-too keen on having their technology stolen.
It could be interesting if the events somehow led to the downfall of Skynet itself (perhaps a predator self-destruct going off inside one of the primary system cores), while the ensuing human renaissance could see the inception of WY and other staples of the alien franchise (Hyperdyne androids perhaps derived from predator tech).
