While I'm in the minority who likes SR a lot, I can understand why others dislike it. However, I've become more and more sure that while there will be another Superman movie, it won't be a sequel to SR and won't feature Bryan Singer behind the camera. If WB were going to make a direct sequel to it, the wheels would have been in motion long before now. Singer and his co-writers, Routh, Bosworth etc would all be booked up. There would have been no talk of a JLA movie and no discussions or pitches from other writers or directors.
I think WB will be looking at the success ofthe Batman franchise, having dumped the baggage of the Burton/Shumacher years, the reinvention of Bond and the success of the breezy, fun-filled Iron Man. While not every reboot is a roaring success - the Incredible Hulk (though it was great fun) - I don't see them greenlighting another movie with Son of Superman and all the stuff that so many disliked in 2006.
I do hope that even if they jettison Singer and the rest of the creative crew behind SR, they retain Brandon Routh. I think he was the perfect successor to Chris Reeve and I think they'd be crazy to spend zillions more dollars seeking a new wearer of the cape when they have the perfect man at home twiddling his thumbs. And with him being a good 3 or 4 years older (at least) by the time shooting begins on any sequel, presumably he won't look like Superboy any more.