Slammer is just another one of those rides that I'd ride with someone if they wanted to, but I was on my own I probably wouldn't bother. It's unique and the sensation is pretty fun, but to be honest I don't think it's that great. If they took it out to put something better in I don't think I'd be particularly disappointed.
As for what's really going on with Slammer, is it still on the park maps for 2012? They could just be giving it a year out and refurbishing (and fixing!) it, so have taken all the sign-age down to prevent any confusion. I did ride it in April when we filmed the CoasterForce POV, so not sure if I'm wrong etc.