Heres a document released for public consumption in 2004 outlining the U.S. Navy's ideas how to use their new AUV/UUV toys.
http://www.navy.mil/navydata/technology/uuvmp.pdf
Its got to be cheaper than building a fleet of Seawolves which was why I think they may have stopped building them. I still see a need for manned submarines as a weapons platform and as suggested a mothership to UUVs and ROVs, but I think only for a short time. I've read they already have in the works plans for UUV motherships now too.
Something else to think about, with an AUV you dont need to pack all of your capability into one vehicle like currently manned submarines have. Instead you can have a multitude of smaller specialized vehicles all thinking and working together as one. Kinda like those scary Perdix autonomous drone swarms, except underwater.
Listen to those Perdix swarm at the end of the video. Imagine if you were on a sub underwater and heard that noise as AUV's swarmed about before the kill. Sounds like something right out of a horror film.