Del Rio has done an incredible job with this D. I don't think the talent on the roster is equal to the performance on the field, so JDR gets tremendous credit for that.
Still, as much as I would like to see him stick around, I wouldn't necessarily tie the future of this franchise to him. There is nothing in experience in JAX to suggest he can lead this team down the road. He's a great coordinator, and leave it at that. Let some other team recycle him as a HC and tread water.